A Snapshot of the World's Water Quality: Towards a Global Assessment

Home , Hydrobiology, Kolyma, Vaal Barrage, Volta River, Water pollution, Water quality

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A Snapshot of the World’s Water Quality: Towards a global assessment A Snapshot of the World’s Water Quality: Towards a global assessment Towards Quality: Water World’s of the A Snapshot UNEP report UNEP report A Snapshot of the World’s Water Quality: Towards a global assessment | UNEP report

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A Snapshot of the World’s Water Quality: Towards a global assessment

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Suggested Citation UNEP 2016. A Snapshot of the World’s Water Quality: Towards a global assessment. United Nations Environment Programme, Nairobi, Kenya. 162pp

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Acknowledgements

UNEP Coordination Hartwig Kremer, Norberto Fernandez (until 2013), Patrick Mmayi, Keith Alverson & Thomas Chiramba (until 2015)

Project Coordination Dietrich Borchardt & Ilona Bärlund Department of Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ

Chief Editor Joseph Alcamo Center for Environmental Systems Research (CESR), University of Kassel

Scientific Editors Joseph Alcamo Center for Environmental Systems Research (CESR), University of Kassel & Dietrich Borchardt Department of Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ

Technical Editor Ilona Bärlund Department of Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ

Contributing Authors Chapter 1 Deborah V. Chapman UNEP GEMS/Water Capacity Development Centre, Environmental Research Institute, University College Cork Joseph Alcamo Center for Environmental Systems Research (CESR), University of Kassel

Chapter 2 Jeanette Völker, Désirée Dietrich & Dietrich Borchardt Department Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ Philipp Saile UNEP GEMS/Water Data Centre, International Centre for Water Resources and Global Change, German Federal Institute of Hydrology Angela Lausch Department Computational Landscape Ecology, Helmholtz Centre for Environmental Research – UFZ Thomas Heege EOMAP GmbH & Co.KG

Chapter 3 Martina Flörke, Joseph Alcamo, Marcus Malsy, Klara Reder, Gabriel Fink & Julia Fink Center for Environmental Systems Research (CESR), University of Kassel Jeanette Völker & Dietrich Borchardt Department of Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ Karsten Rinke Department of Lake Research, Helmholtz Centre for Environmental Research – UFZ

Chapter 4 Ilona Bärlund Department Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ Marcelo Pires da Costa National Water Agency of Brazil Upper Tietê Prasad Modak Environmental Management Centre LLP, Mumbai Godavari Adelina M. Mensah & Chris Gordon Institute for Environment and Sanitation Studies (IESS), University of Ghana Volta Mukand S. Babel Water Engineering and Management, Asian Institute of Technology & Pinida Leelapanang Kamphaengthong Water Quality Management Bureau, Pollution Control Department, Ministry of Natural Resources and Environment, Thailand Chao Phraya Chris Dickens International Water Management Institute (IWMI), South Africa Vaal Seifeddine Jomaa Department of Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ Sihem Benabdallah Centre de Recherches et des Technologies des Eaux, Tunisia & Khalifa Riahi Laboratory of Chemistry and Water Quality, Department of Management and Environment, High Institute of Rural Engineering and Equipment, University of Jendouba Medjerda Gregor Ollesch Elbe River Basin Community, Magdeburg Elbe Dennis Swaney Department of Ecology & Evolutionary Biology, Cornell University Karin Limburg Department of Environmental and Forest Biology, State University of New York College of Environmental Science & Forestry & Kevin Farrar NY State Department of Environmental Conservation, Division of Environmental Remediation Hudson Joseph Alcamo Center for Environmental Systems Research (CESR), University of Kassel

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Chapter 5 Dietrich Borchardt Department Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ Chris Gordon & Adelina M. Mensah Institute for Environment and Sanitation Studies, University of Ghana Jesper Goodley Dannisøe DHI Roland A. Müller Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research – UFZ Joseph Alcamo Center for Environmental Systems Research (CESR), University of Kassel

Advisory Committee, participants of two Advisory Committee meetings March 2014 & January 2015

AC1 & AC2 Mukand Babel Asian Institute of Technology Peter Koefoed Bjørnsen UNEP-DHI, Denmark Deborah V. Chapman UNEP GEMS/Water Capacity Development Centre, Environmental Research Institute, University College Cork Johannes Cullmann UNESCO-IHP and German Federal Institute of Hydrology Chris Dickens International Water Management Institute (IWMI), South Africa Javier Mateo Sagasta Divina International Water Management Institute (IWMI) Sri Lanka Sarantuyaa Zandaryaa UNESCO Division of Water Science

AC2 only Marcelo Pires da Costa National Water Agency of Brazil Sara Marjani Zadeh FAO

AC1 only Fengting Li Tongji University, People’s Republic of China Monica Perreira Do Amaral Porto University of São Paulo Julius Wellens-Mensah WMO Department of Climate and Water Hua Xie International Food Policy Research Institute USA

Reviewers

Salif Diop Université CAD Dakar, Sénégal Alan Jenkins NERC-CEH, UK Mick Wilson UNEP Chief Scientist’s Office Hong Yang Eawag, Switzerland Sara Marjani Zadeh FAO Javier Mateo Sagasta Divina IWMI Kate MedlicottWHO Cecilia Scharp UNICEF

Funding The Government of Norway and the Government Canada through its Environment Canada as well as UN Water are gratefully acknowledged for providing the necessary funding that made the production of this publication“A Snapshot of the World’s Water Quality: Towards a global assessment” possible.

For more information see: www.wwqa-documentation.info

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Foreword: A Snapshot of the World’s Water Quality “Towards a global assessment” Flowing knowledge The quality of surface water in many parts of the significant risk to vital activities like inland fishing, which developed world has noticeably improved in recent accounts for some 60 million jobs and almost a third of decades, but is being challenged as economic growth, fish harvested for human consumption. demographics and climate change lead to widespread Sound knowledge is critical to understanding the and severe degradation. The need to reverse this underlying causes and developing the evidence based damage is reflected in the 2030 Agenda for Sustainable policies to improve it, including source control, waste Development, both as a dedicated goal and as an integral treatment, ecosystem management and new forms of element of many others. By providing a snapshot of local and global governance. Yet, until now, insufficient the current situation, this report offers a baseline to collection and evaluation of data has made it difficult measure progress, a framework for global assessment to grasp the intensity and scope of deteriorating and a pathway towards sustainable solutions that will water quality. While an overview of the situation in deliver on that agenda. the Southern Hemisphere already feeds into UNEP’s With many rivers still in good condition, there are Global Environment Outlook, this report clarifies opportunities to prevent pollution and begin restoration. methodology and priorities for data collection, gaps and However, severe organic pollution is already affecting scale. Focussing on key hot spots, it applies advanced around one in seven rivers across Latin America, Africa modelling to existing information, which will assist and Asia. This poses a growing risk to public health, food countries looking to establish their own planning, security and the economy, while cultivating inequality by monitoring and guidelines. predominantly affecting the poor, women and children. Thanks to support from UN Water and the many Freshwater systems in both developed and developing contributing authors, this report will help bridge nations face growing pressure from the discharge the gap between water quality, the inclusive green of harmful chemicals, such as hormone disrupters. economy and wider development issues. I hope that by Unfortunately, municipal water treatment has become combining such a global issue with local understanding, increasingly costly and developing countries in it will provide public and private sector decision makers particular have problems matching expanding public a practical tool to deliver on all of the water related water supplies and sewerage, with adequate treatment commitments for the 2030 Agenda. of the new wastewater flows. As a result, there is a

Achim Steiner, United Nations Under-Secretary-General and UNEP Executive Director

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Table of Contents

Acronyms …………………………………………………………………………………………………………………………………………………………IX Executive Summary in Arabic …….…………..………………………………………………………………………………..……………………XV Executive Summary in Chinese ….……….………………………………………...... …………………………………………………………XXII Executive Summary in English ………..………………………………………...... ………….……………………………………XXVIII Executive Summary in French ……………………………………………………………………………………………………………………XXXV Executive Summary in Russian ………...…………………………………………………………………………………………………………XLIII Executive Summary in Spanish ………………………………………………………………………………………………....……………………LI

1 Introduction ………………………………………………………………………………………………………………………………………..…………3

2 State of observational knowledge ………………………………………………………………………………………………..…………………7 2.1 Why do we need global data? ………………………………………………………………………………………………………………..……7 2.2 What data are available from GEMS/Water? ………………………………………………………………………………………………..8 2.2.1 GEMS/Water Programme and GEMStat ……………………………………………...…………………………………………..8 2.2.2 Review of data availability (status 2014) ………………………………………………………………………………………..8 2.3 Can data from the scientific literature help fill the data gap? ………………………………………………………………..10 2.4 What is the potential of remote sensing? ………………………………………………………………………………………………11 2.5 How can more data be made available? ...... ……………………………………………………………………………………12

3 Water pollution on the global scale ………………………………………………………………………………………………………………15 3.1 Introduction: A combined data and modelling approach ………………………………………………………………………15 3.2 Pathogen pollution and the health risk …………………………………………………………………………………………………17 3.2.1 What health risks are related to polluted water? ……………………………………………………………………………17 3.2.2 What is the level of pathogen pollution? ………………………………………………………………………………………18 3.2.3 People at risk of pathogen river pollution ………………………………………………………………………………………22 3.2.4 Sources of faecal coliform bacteria ………………………………………………………………………………………………22 3.3 Organic pollution and the threat to the inland fishery and food security ………………………………………………25 3.3.1 What is organic pollution? ……………………………………………………………………………………………………………25 3.3.2 The importance of inland fisheries to food security …………………………………………………………………………25 3.3.3 What is the level of organic pollution? ……………...………………………………………………………………………29 3.3.4 Sources of organic pollution …………...…………………………………………………………………………………………35 3.4 Salinity pollution and impairment of water use ……………………………………………………………………………………37 3.4.1 What is salinity pollution and how does it impair water use? ……...... …………………………………………37 3.4.2 What is salinity pollution and how does it impair water use? ……...... …………………………………………38 3.4.3 Sources of salinity pollution ……………………………………...... ……………………………………………………………41 3.5 Eutrophication and nutrient loadings to large lakes ………………………………………………………………………………43 3.5.1 What are eutrophication and other water quality problems in lakes?……………………………………………43

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3.5.2 What are the phosphorus loadings to major world lakes? …………………………………………………………44 3.5.3 What are the sources of phosphorus? ……………………...... ………………………………………………………………45

4 Water Pollution in River Basins ……………………………………………………………………………………………………………………49 4.1 Introduction ……….…………………………………………………………………………………………………………………………………49 4.2 River Basin 1 – Upper Tietê …………………………………………………………………………………………………………………..54 4.2.1 Brief overview of Upper Tietê Basin characteristics and governance ……………………………………………..54 4.2.2 Typical water pollution problem, causes and impacts ………………………………………………………………..55 4.2.3 Solutions and transferable lessons ……………………………………………………………………………………………..56 4.3 River Basin 2 – Godavari ………………………………………………………………………………………………………………………..57 4.3.1 Brief overview of Godavari Basin characteristics and governance ……………………………………………..57 4.3.2 Typical water pollution problems, causes and impacts ………………………………………………………………..57 4.3.3 Solutions and transferable lessons ……………………………………………………………………………………………..58 4.4 River Basin 3 – Volta ……………………………………………………………………………………………………………………………..59 4.4.1 Brief overview of Volta Basin characteristics and governance …………………………………………………..59 4.4.2 Typical water pollution problem, causes and impacts ………………………………………………………………..60 4.4.3 Solutions and transferable lessons ……………………………………………………………………………………………..61 4.5 River Basin 4 – Chao Phraya ………………………………………………………………………………………………………………..63 4.5.1 Brief overview of Chao Phraya Basin characteristics and governance ………………………………………..63 4.5.2 Typical water pollution problem, causes and impacts ………………………………………………………………..63 4.5.3 Solutions and transferable lessons ……………………………………………………………………………………………..65 4.6 River Basin 5 – Setting resource quality objectives for the Vaal River …...... ………………………………………..66 4.6.1 Brief overview of Vaal Basin characteristics and governance ……………………………………………………..66 4.6.2 Salinity pollution in the Vaal River, causes and impacts ……………………………………………………………..67 4.6.3 Solutions and transferable lessons ……………………………………………………………………………………………..67 4.7 River Basin 6 – Medjerda ………………....…………………………………………………………………………………………………..69 4.7.1 Brief overview of Medjerda Basin characteristics and governance ……………………………………………..69 4.7.2 Typical water pollution problem, causes and impacts …………………………………………………...... 69 4.7.3 Solutions and transferable lessons ……………………………………………………………………………………………..71 4.8 River Basin 7 – Elbe ………………....…………………………………………………………………………………………………………..71 4.8.1 Brief overview of Elbe characteristics and governance ……………………………………………………………..71 4.8.2 Typical water pollution problems, causes and impacts ………………………………………………………………72 4.8.3 Solutions and transferable lessons ……………………………………………………………………………………………..74 4.9 River Basin 8 – Hudson ………...... ………………………………………………………………………………………………………..75 4.9.1 Brief overview of Hudson Basin characteristics and governance …………………………………………………..75 4.9.2 PCBs: causes and impacts …………………………………………………………………………………………………………..76 4.9.3 Solution(s) and transferable lessons …………………………………………………………………………………………..77 4.10 General conclusions from the case studies ……………………………………………………………………………………..79

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5 Solutions to the Water Quality Challenge: A Preliminary Review …………………………………………………………………..81 5.1 Technical Options ……………………………………………………………………………………………………………………………..81 5.1.1 Pollution prevention …………….……………………………………………………………………………………………………..84 5.1.2 Treatment of wastewater …….……………………………………………………………………………………………………..85 5.1.3 Safe reuse of wastewater ………….………………………………………………………………………………………………..86 5.1.4 Protection and restoration of ecosystems …………………………………………………………………………………..88 5.2 Other issues for protecting water quality …………....………………………………………………………………………………..90 5.2.1 Water quality protection and the Post-2015 Development Agen…………………………………………………..90 5.2.2 Precedents for restoration ………...………………………………………………………………………………………………..90 5.2.3 Financing and governance for protecting and restoring freshwate………………………………………………..90 5.3 Some questions for a full assessment ……………………………...…………………………………………………………………..93

Literature ………………………………………………………………………………………………………………………………………………………..95

Appendix …………………………………………………………………………………………………………………………………………………Appendix_1

Appendix A ……………………...……………………………………………....………….……………………………………………………Appendix_3

A1 Available data from GEMStat (1990–2010) …………..………………………………………………………………Appendix_3

Appendix B ………………..………………………………………...... …………………………………………………………………………Appendix_6

B1 WorldQual – model description ...... …Appendix_6

B1.1 The modelling framework ……...………...……………………………………………………………………………Appendix_6

B1.2 Pollution loadings ……………...……....…………………………………………………….……………………………Appendix_7

B1.2.1 Sources of pollution ……………...…………………………………………………………………………………Appendix_7

B1.2.2 Domestic sewered sector ….……………………………………………………………………………………Appendix_7

B1.2.3 Domestic non-sewered sector ...………………………………………………………………………………Appendix_8

B1.2.4 Manufacturing sector …………...…………………………………………………………………………………Appendix_9

B1.2.5 Urban surface runoff ……………...…………………………………………………………………………………Appendix_7

B1.2.6 Agricultural inorganic fertilizer…...……………………………………………………………………………Appendix_10

B1.2.7 Agricultural livestock wastes …..………………………………………………………………………………Appendix_10

B1.2.8 Agricultural irrigation ……………..………………………………………………………………………………Appendix_10

B1.2.9 Background loadings ………………………………………………………………………………………………Appendix_10

B1.3 Calculation of in-stream concentrations …….…..……………………………………………………………Appendix_11

B1.4 TP retention in surface waters ……………...... ……………………………………………………………Appendix_11

B1.5 Model testing ………………………………………………….………………………………………………………………Appendix_11

B2 Water quality standards ………..………………………...……………………………………………………………………Appendix_15

B3 Literature on vulnerable groups …….....……………….…………………………………………………………………Appendix_17

B4 Lake data ………………….……………………..……………………………………………………………………………………Appendix_18

B5 References ………….....………………………....…………………………………………………………………………………Appendix_19

Appendix C ………..……………………....……………………………………………………………………………………………………Appendix_26

C1 Case study 4 – Chao Phraya …………....……………………………………………………………………………………Appendix_26

C2 Case study 5 – Vaal ……………………...………………………………………………………………………………………Appendix_27

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Buch_UNEP_vordere_Kapitel_1504.indb 10 09.05.16 17:12 Acronyms

Acronyms

Table of abbreviations

Stands for Notes AMCOW African Ministerial Council on Water BFG (German) Federal Institute of Hydrology BOD Biochemical oxygen demand Used to estimate the number of viable CFU Colony-forming unit bacteria, here faecal coliform bacteria. DEWA Division of Early Warning and Assessment UNEP Division DO Dissolved oxygen Causal framework, adopted by the EEA, for Drivers, Pressures, States, Impacts, DPSIR describing the interactions between society Responses and the environment Economic Community Of West African ECOWAS States EEA European Environment Agency Food and Agriculture Organization of the FAO United Nations FC Faecal coliform bacteria FD (European) Floods Directive FishstatJ Fishery and Aquaculture Global Statistics FAO database GDP Gross domestic product (United Nations) Global Environment http://www.unep.org/gemswater/Home/ GEMS/Water Monitoring System on Water tabid/55762/Default.aspx GEMStat Global Environment Monitoring Statistics Global water quality database http://themasites.pbl.nl/tridion/en/ HYDE History Database of the Global Environment themasites/hyde/ JMP Joint Monitoring Programme WHO/UNICEF activity MOdelling Nutrient Emissions in RIver http://www.moneris.igb-berlin.de/index.php/ MONERIS Systems homepage.html N Nitrogen

NH3-N Ammonia nitrogen (un-ionised) + NH4 -N Ammonia nitrogen (ionised) Facilitator of data flow between GEMS and NFP National Focal Point national states NGO Non-governmental organisation NRS National Reporting System UNEP activity P Phosphorus PCB Polychlorinated biphenyl

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Stands for Notes The SDGs were first formally discussed at the SDG Sustainable Development Goals UN Conference on Sustainable Development held in Rio de Janeiro in June 2012 (Rio+20) TC Total coliform bacteria TN Total nitrogen TP Total phosphorus TDS Total dissolved solids UN United Nations UNEP United Nations Environment Programme United Nations Educational, Scientific and UNESCO Cultural Organization The United Nations inter-agency mechanism UN-Water for all freshwater related issues, including sanitation WaterGAP Water – Global Assessment and Prognosis Model used in the Assessment, see Appendix B WFD (European) Water Framework Directive WHO World Health Organization WMO World Meteorological Organization Water quality model embedded in WaterGAP WorldQual modelling framework, and used in this report. See Appendix B WWAP World Water Assessment Programme WWQA World Water Quality Assessment WQI Water Quality Index

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ِٛ جض رٕف١زٞ جض رٕف ١ز ٞ

اٌشعبئً األعبع١خ

. رؼذ ١ػٛٔخ ١ِبٖ اٌغ١ذح ِغ رٛفش و١ّخ وبف١خ ِٓ اٌّبء ػشٚس٠خ عذا ٌزؾم١ك أ٘ذاف اٌز١ّٕخ اٌّغزذاِخ ِٓ أعً اٌظؾخ ٚاألِٓ اٌغزائٚ ٟاألِٓ اٌّبئٚ .ٌٟزٌه رفبلُفئْ رٍٛس اٌّبء ِٕز اٌزغ١ٕ١ؼبد فؼِ ٟظُ أٙٔبس أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب آع١بٚ ِض١ش عذا ٌٍمٍك. . ِٚٓ اٌُّٙ أْ رشرجؾ اإلعشاءاد اٌالصِخ ؾٌّب٠خ ١ػٛٔخ ا١ٌّبٖ ِغاعزؼبدٚ رٙب اٌغٛٙد اٌشا١ِخ إٌٝ أ٘ذافرؾم١ك اٌز١ّٕخ اٌّغزذاِخ ِٚغ عذٚي أػّبي اٌز١ّٕخ ٌّب ثؼذ ػبَ .2015 . اٌزٍٛس٠ؤصش اٌّّشع اٌشذ٠ذ ثبٌفٍٝػ ًؼ صٍش ِغًّ ِغبؽبد أٙٔبس أِش٠ىب اٌالر١ٕ١خ آع١بٚأفش٠م١ب ٚ . ثبإلػبفخ إٌٝ اٌّخبؽش اٌظ١ؾخ إٌبعّخ ؽ ٓػش٠ك ششة ا١ٌّبٖ اٌٍّٛصخ فئْ إٌبطوض١ش ِٓ ؼ٠شٛػْ أٔفغُٙ ٌخطش اٌّشع ػٓ ؽش٠ك ِالِغخ ا١ٌّبٖ اٌغط١ؾخ اٌٍّٛصخ ػٕذ االعزؾّبَ ٚرٕظ١ف اٌّالثظ ِّٚبسعخ األٔشطخ إٌّض١ٌخ األخشٚ . ٜلذ . ٚ ٠زشاػ ػٚذد عىبْ س٠ف ٘زٖ اٌمبساد اؼٌّشٙ ٛػزٖثْ ٌٍخطش اٌطش٠مخ إٌٝ ِئبد اٌّال١٠ٓ. . ٠ؤصش اٌزٍٛس اٞٛؼؼٌ اٌشذ٠ذ ؽب١ٌب ٛؽ ٍٝػاٌٟ عضء ِٓ عجؼخ أعضاء ٌّغًّ ِغبؽبد أٙٔبس أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب

ٚ ٚآع١ب ٠شىً ِظذس لٍك ألٔشطخ ط١ذ اٌغّه فٟ ا١ٌّبٖ اؼٌزثخ ٛف١شزٌٚثبٌزبٌٟ األِٓ اٌغزائٚ ٟعجً وغت ا١ؼٌش أؼ٠ب. . ٠ؤصش اٌزٍٛس ثبألِالػ اٌشذ٠ذ ٚاؼٌّزذي ٍٝػ عضء ِٓ ػششح أعضاء ٌّغًّ ِغبؽبد أٙٔبس أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚ ٚآع١ب ٠ض١ش اٌمٍك ألٔٗ ٛؼ٠ق اعزخذاَ ١ِبٖ األٙٔبس ألغشاع اٌشٚ ٞاٌظٕبػخ ٚغ١ش٘ب ِٓ االعزخذاِبد. . ٠ىّٓ اٌغجت اٌّجبشش فٟ ص٠بدح رٍٛس ا١ٌّبٖ فٟ رضا٠ذ و١ّبد اٌّخٍفبد اٌغبئٍخ داخً األٙٔبس ٚاٌج١ؾشاد . أِب األعجبة األعبع١خ فٟٙ إٌّٛ اٌغىبٚ ٟٔص٠بدح إٌشبؽ االلزظبدٚ ٞرىض١ف اٌضساػخ ٚرٛعٙؼب ٚرضا٠ذ شجىبد اٌظشف اٌظٟؾ راد اٌّغزٜٛ ا١ؼؼٌف أٚ اؼٌّٕذَ ؼٌّبٌغخ اٌفؼالد اٌغبئٍخ. . رشىً إٌغبء إؽذٜ اٌفئبد األوضش رأصشا ثزذٛ٘س ١ػٛٔخ ا١ٌّبٖ فٟ اٌجٍذاْ إٌب١ِخ ثغجت اعزخذاِٙٓ اٌّزىشس ١ٌٍّبٖ فٟ اٌزذث١ش إٌّضٚ ٌٟأؼ٠ب األؽفبي ثغجت ؼٌجُٙ فٟ ا١ٌّبٖ اٌغط١ؾخ ا١ٍؾٌّخ ٚألُٙٔ وض١شا ِب ٠زِٙ ٌّْٛٛخ عّغ ا١ٌّبٖ ٌألػّبي إٌّض١ٌخ، ٚوزٌه عىبْ اٌش٠ف رٚ اٌذخً إٌّخفغ اٌز٠ٓ ٠غزٍٙىْٛ األعّبن وّظذس ٘بَ ٌٍجشٚر١ٓ ثبإلػبفخ إٌٝ اٌظ١بد ٠ٓ رٞٚ اٌذخً اؾٌّذٚد ػّٚبي ط١ذ اٌغّه اٌز٠ٓ ؼ٠زّذٍٝػ ْٚ اٌظ١ذ فٟ ا١ٌّبٖ اؼٌزثخ ٌىغت سصلُٙ. . ٍٝػٚ اٌشغُ ِٓ خطٛسح ػٚغ رٍٛس ا١ٌّبٖ ٚاٌزٞ ٠ضداد عٛءا فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآع١ب فئْ غبٌج١خ أٙٔبس ٘زٖ اٌمبساد اٌضالس ال رضاي فؽ ٟبٌخ ع١ذح، ٕٚ٘بٌه فشص وج١شح ؾٌٍذ ِٓ اٌزٍٛس ثطشق لظ١شح اٌّذٚ ٜإلطالؽ ػبٌخ اٌٍّٛصخاألٙٔبس . ٚعزؾزبط ٘زٖ اٌّٙبَ إٌٝ عّغ اإلداسح اٌغ١ذح ِغ خ١بساد رم١ٕخ ِذٛػِخ ِٓ ؽىِٛخ عذ٠شح ثٙزٖ اٌّغؤ١ٌٚخ . ٠زٛفش ٌٍجٍذاْ إٌب١ِخ ٔطبق ٚاعغ ِٓ اٌخ١بساد اإلداس٠خ ٚاٌف١ٕخ ٌّىبفؾخ رٍٛس ا١ٌّبٖ. ٌُٚ رىٓ اٌىض١ش ِٓ ٘زٖ اٌخ١بساد ِزٛفشح أٚ ِغزخذِخ ِٓ لجً اٌذٚي اٌّزمذِخ ػٕذِب ٚاعٙذ ٌرذٛ٘سا ِّبصال ١ػٕٛخ ا١ٌّبٖ لجً ثؼؼخ ػمٛد. . ال غػ ٕٝٓ ِشالجخ ١ػٛٔخ ا١ٌّبٖ ٚرمّٙ١١ب ٌفُٙ شذح اٌزؾذٞ اؼٌب١ػٌٕٛ ٌّٟخ ا١ٌّبٖ .ٚٔطبلٗ. ث١ذ أْ رغط١خ اٌج١بٔبد فٟ أعضاء وض١شح ِٓ اؼٌبٌُ ال رىفٌٙ ٟزا اٌغشع .ٍٝػ عج١ً اٌّضبي فئْ وضبفخ ؾِطبد ل١بط ١ػٛٔخ ا١ٌّبٖ فٟ أفش٠م١ب ألً ِبئخ ِشح ِٓ اٌىضبفخ اٌّغزؼٍّخ ٌٍّشالجخ فٟ أِبوٓ أخشٜ ِٓ اؼٌبٌُ. ٌزا فئٔٗ ِٓ اؼٌشٚسٞ دػُ عّغ اٍٛؼٌِّبد ٛؽي ١ػٛٔخ ٚرٛصؼ٠ا١ٌّبٖ ٙب ٚرٍٙ١ٍؾب ِٓ خالي ثشٔبِظ إٌظبَ اؼٌبٌّٟ ٌشطذ اٌج١ئخ/ ا١ٌّبٖ اؼٌّشٚف ثبعُ GEMS/Water ٚغ١شٖ ِٓ األٔشطخ. ٠ّٚىٓ اعزخذاَ ثؤس اإل٘زّبَ اٌّ ؼ ش فخ فٟ ٘زا اٌزمش٠ش ٌزؾذ٠ذ األ٠ٌٛٚبد ػٕذ عّغ اٌج١بٔبد.

Buch_UNEP_vordere_Kapitel_1504.indb 15 09.05.16 17:12 A Snapshot of the World’s Water Quality: Towards a global assessment | UNEP report

٠زطٍت اٌجشش ٚإٌظُ اٌج١ئ١خ ٍٝػ حذ سٛاء و١ّخ وبف١خ ِٓ ا١ٌّبٖ ثبإلظبفخ إ١ػٛٔ ٌٝخ ِالئّخ ِٕٙب. ٚثبٌزبٌٟ، ٕ٘بن ظشٚسح ٍِحخ ٌزحذ٠ذ األِبوٓ اٌزٟ رؼب١ػٛٔ ِٓ ٟٔخ ١ِبٖ غ١ش ِالئّخ أِٙ ٚذدح ٚوزٌه إلدساط اٌحبجخ إ١ػٛٔ ٌٝخ ج١ذح١ِبٖ فٟ ِفَٛٙ األِٓ اٌّبئ٠ٚ .ٟشوض ٘زا اٌزمش٠ش ١ػٛٔ ٍٝػخ ا١ٌّبٖ ػٚاللزٙب ثأ٘ذاف اٌز١ّٕخ ِضً اٌصحخ ٚاألِٓ اٌغزائٟ اٌّبئٟٚاألِٓ . . ٌٚشثػ ٘زٖ اؼٌاللخ ٠سزؼشض اٌزمش٠ش اٌّشبوً األسبس١خ ١ػٕٛخٌ ا١ٌّبٖ اٌسطح١خ ثّب فٟ رٌه اٌزٍٛس اٌّّشض، ٚاٌزٍٛس اؼٌعٚ ٞٛاٌزٍٛس ثبألِالح ٚاإلصشاء اٌغزائ٠ٚ . ٟٕصت اٌزشو١ض ٕ٘ب ٍٝػ صالس لبساد ُ٘ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآس١ب.

ٌوبْ ذػُ األِٓ اٌّبئٟ أ٠ٌٛٚخ د١ٌٚخ ٍٝػ ِذٜ اٌغٕٛاد اٌّب١ػخ فّٓ خالي األ٘ذاف اإلّٔبئ١خ ٌألٌف١خ ٚغ١ش٘ب ِٓ األػّبي أػطٝ اٌّغزّغ اٌذٌٟٚ األ٠ٌٛٚخ ٌٍغبٔت اٌىّٟ ٌألِٓ اٌّبئٚ ٟرٌه ِٓ خالي رٛع١غ اٌغجً ٌٛطٛي إٌبط إٌٝ إِذاداد ِأِٛٔخ ١ٌٍّبٖ. فؼال فئْ رٛط١ً و١ّخ ا١ٌّبٖوبف١خ ِٓ ٌٍجشش ٌٍٕٚشبؽ اٌظٕبٚ ٟػاٌضساٟػ ؼ٠ذ ٚال ثذ أْ ٠جمٝ رٚ أ٠ٌٛٚخ د١ٌٚخ ػب١ٌخ. ِٚغ رٌه رضداد أ١ّ٘خ ِم١بط آخش ٌألِٓ اٌّبئٟ – ٟأال ٚ٘ اٌزأوذ ِٓ ا١ػٌٕٛخ اٌىبف١خ ١ٌٍّبٖ ٚاؼٌزثخ. ؼ٠زجش ٘زا أِشا ِّٙب ألْ ١ػٛٔخ ١ِبٖ األٙٔبس ٚاٌج١ؾشاد فٟ اؼٌبٌُ رّش ثزغ١١شاد ثبٌغخ. ٚرؼٕىظ األ اٌّزض٠ٌٛٚخ ٌا٠ذح ١ػٕٛخ ا١ٌّبٖ فٟ اٌّمبطذ اٌّخزٍفخ أل٘ذاف اٌز١ّٕخ اٌّغزذاِخ.

ٌمذ رؾغٕذ ١ػٛٔخ ا١ٌّبٖ ثشىً ٛؾٍِظ فٟ وض١ش ِٓ اٌجٍذاْ اٌّزمذِخ ٍٝػ اٌشغُ ِٓ أْ ثؼغ اٌّشبوً ال رضاي لبئّخ. ٚفٟ غٛؼْ رٌه ١ّ٠ً اػٌٛغ فٟ اٌجٍذاْ إٌب١ِخ إٌٝ ص٠بدح رٍٛس ا١ٌّبٖ ٔظشا ٌٍّٕٛ اٌغىبٟٔ فٟ إٌّبؽك اؼؾٌش٠خ ٚص٠بدح االعزٙالن اٌّبدٚ ٞأزشبس و١ّبد ١ِبٖ اٌظشف اٌظٟؾ غ١ش اؼٌّبٌغخ. ٌىٓ ثغجت ٔمض اٍٛؼٌِّبد األعبع١خ ال ٠ّىٓ إال رخ١ّٓ اػٌٛغ اؾٌب١ػٌٕٛ ٌٟخ ا١ٌّبٖ فٟ وض١ش ِٓ إٌظُ اٌج١ئ١خ ١ٌٍّبٖ اؼٌزثخ فٟ ٘زا اؼٌبٌُ. ١ٍػٚٗ فئْ ٕ٘بن ؽبعخ ؾٍِخ إٌٝ إعشاء رم١١ُ ٌزؾذ٠ذ ٔطبق ؽٚغُ "اٌ زؾذٞ ٌاؼٌب١ػٕٛ ٌّٟخ ٚا١ٌّبٖ " ٙذفر. ٘زٖ اٌذساعخ اٌز١ّٙذ٠خ إٌٝ رٛف١ش ثؼغ اؼٌٕبطش األعبع١خ ٌزشى١ً رم١١ُ شبًِ إٌطبق ١ػٌٕٛخ ا١ٌّبٖ اؼٌب١ٌّخ ٚاٌزٞ ٠ّىٓ رط٠ٛشٖ إٌٝ رم١١ُ ِىزًّ. روّب ؼشع ٘زٖ اٌذساعخ اٌز١ّٙذ٠خ اأؼ٠ب رمذ٠ش أ١ٌٚب ػٛغٌ ١ػٛٔخ ا١ٌّبٖ فٟ إٌظُ اٌج١ئ١خ اؼٌب١ٌّخ ١ٌٍّبٖ اؼٌزثخ ِغ اٌزشو١ض ٍٝػ األٙٔبس ٚاٌج١ؾشاد فٟ صالس لبساد.

رفبلُ رٍٛس ا١ٌّبٖ ِٕز رس١ٕ١ؼبد اٌمشْ اٌّبظٟ فؼِ ٟظُ أٙٔبس أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآس١ب1.

ذسدٌمذ ل اٌزغ١١شاد فٟ اٌفزشح ِب ث١ٓ ٚ 1990 2010 ثبعزخذاَ ؼِبٌُ األٙٔبس اٌشئ١غ١خ اٌزٟ رؼىظ ِذٜ اٌزٍٛس اٌّّشع )ثىزش٠ب ل١ٌٔٛٛخ غبئط١خ ( ٚاٌزٍٛس اٞٛؼؼٌ )اٌطٍت اٌجٌٛٛ١عٟ اٌى١ّ١بئٍٝػ ٟ األوغغ١ٓ؛ اؼٌّشٚف ثبعُ ٚ ) BODاٌزٍٛس ثبألِالػ )ِغّٛع اٌّٛاد اٌّزاثخ اؼٌّشٚف ثبعُ TDS(. ٌمذ رذٛ٘س ِغزٜٛ اٌزٍٛس اٌّّشع ٚاٌزٍٛس اٞٛؼؼٌ فٟ أوضش ِٓ 50 فٟ اٌّبئخ ِٓ ِغبؽبد األٙٔبس فٟ ع١ّغ اٌمبساد اٌضالس، ف١ؽ ٟٓ عبء اٌزٍٛس ثبألِالػ فٟ ِب ٠مشة صٍش ٘زٖ اٌّغبؽبد2. إْ اػٌٛغ اٌغٟء أعضاءٌجؼغ ّغبؽبد٘زٖ اٌ ٠ض١ش اٌمٍك ثشىً خبص ١ؽش اصداد رٍٛس ا١ٌّبٖ ٕ٘بن إٌٝ ِغزٜٛ شذ٠ذ أٚ وبْ أطال ٍٝػ ِغزؽ ٛبد فػ ٟبَ 1990 صُ رفبلُ ثٍٛؾي ػبَ 2010 . . 2010

٠ؤصش اٌزٍٛس اٌّّشض اٌحبد3 حب١ٌب ٍٝػ ِب ٠مشة صٍش ِجًّ ِسبحبد األٙٔبس فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآس١ب. ٚ٠لذ صً ػذد سىبْ اٌش٠ف اٌز٠ٓ ٛ٠اجْٛٙ أخطبس صح١خ ثسجت اإلرصبي ثب١ٌّبٖ اٌسطح١خ اٌٍّٛصخ إٌٝ ِئبد اٌّال١٠ٓ فٟ ٘زٖ اٌمبساد. إٌسبء ٚاألغفبي ُ٘ ِٓ ث١ٓ أوضش اٌفئبد اٌّٙذدح ٕ٘بن.

٠مذس أْ اٌزٍٛس اٌّّشع اٌشذ٠ذ ١ؽش رض٠ذ اٌزشو١ضاد اٌشٙش٠خ ٌٍجىزش٠ب اٌم١ٌٔٛٛخ اٌغبئط١خ ا١ٌّبٖفؽٚ 1000 ٍٝػ ٟذح رشى١ً ِغزؼّشح ٌىً 100 ١ٍٍِزش4 ( ٠ؤصش ٛؾٔ ٍٝػ سثغ ِغبؽبد أٙٔبس أِش٠ىب اٌالر١ٕ١خ ٛؾٔ ٍٝػٚ 10 إٌٝ 25 فٟ اٌّبئخ ِٓ ِغبؽبد األٙٔبس األفش٠م١خ ٛؽ ٍٝػٚاٌٟ صٍش إٌٝ ٔظف ِغبؽبد األٙٔبس ا٢ع٠ٛ١خ. ٚثبٌزبٌٟ ٠جذٚ أْ اؾٌذ األٍٝػ ٌٍزٍٛس اٌّّشع ِٓ ث١ٓ ٘زٖ اٌمبساد اٌضالس ٠مغ فٟ آع١ب. ٚإرا أخزٔب ث١ؼٓ االػزجبس ٔغجخ اٌغىبْ اٌش٠ف١١ٓ اٌز٠ٓ ٠زظٍْٛ ١ّبٖثبٍٝػٌ األغٍت اٌغط١ؾخ5 فئْ ِٓ اٌّمذس أْ لشاثخ 8 إ25 ٌٝ ٛ١ٍِْ شخض فٟ أِش٠ىب اٌالر١ٕ١خ ٚ 32 إ164 ٌٝ ٛ١ٍِْ شخض فٟ أفش٠م١ب ٚ 31 31 إ134 ٌٝ ٛ١ٍِْ شخض فٟ آع١ب ُ٘ فٟ خطش. ٘زا اٌّذٜ اٌٛاعغ ٌٙزٖ اٌزمذ٠شاد إّٔب ٠ش١ش إٌٝ أْ اؼٌذ٠ذ ِٓ ٛػاًِ اٌخطش

٠1غزخذَ ٘زا اٌزمش٠ش إٌّبؽك اٌفش١ػخ اٌزب١ٌخ اٌّغزخذِخ فٟ ِششٚع رٛ لؼبد اٌج١ئخ اؼٌب١ٌّخ ٌجشٔبِظ األُِ اٌّزؾذح ٌٍج١ئخ )UNEP ١ٔٛ٠ت( ٌزؾذ٠ذ "أِش٠ىب اٌالر١ٕ١خ"، "أفش٠م١ب"، ٚ "آع١ب": أِش٠ىب اٌالر١ٕ١خ = أِش٠ىب اٌٛعطٝ ,أِش٠ىب اٌغٕٛث١خ ,ِٕطمخ اٌجؾش اٌىبس٠جٟ؛ أفش٠م١ب = ٚعؾ أفش٠م١ب، ششق أفش٠م١ب، شّبي أفش٠م١ب، عٕٛة أفش٠م١ب، غشة أفش٠م١ب، غشة اؾ١ؾٌّ إٌٙذٞ؛ آع١ب = آع١ب اٌٛعطٝ ,شّبي ششق آع١ب ,عٕٛة آع١ب ,عٕٛة ششق آع١ب ، ِٕطمخ غشة آع١ب )شجٗ اٌغض٠شح اؼٌشث١خ، اٌّششق اؼٌشثٟ(

2 ٠غزخذَ ٘زا اٌٍّخض أػذاد ِمشثخ ٌٛطف ٔزبئظ اٌز١ٍؾالد. فئْ ِٓ إٌّبعت ػشع ٔزبئظ ِمشثخ ٌّشاػبح أٚعٗ ػذَ ا١ٌم١ٓ ١ػٛٔخاٌّٛ فٟ اٌزمذ٠شاد اٌزٟ لبِذ ٙ١ٍػب ٘زٖ إٌزبئظ. ٚرؼشع ٘زٖ اٌزمذ٠شاد ا١ّٕؼٌخ فٟ إٌض اٌشئ١غٟ

3 ؼ٠شف ِظطؼٍ اٌزٍٛس اٌّّشع اؾٌبد سلُفٟ اؾٌبش١خ 5 .إْ اٌّغزٜٛ اؼٌبٌٟ ِٓ اٌجىز١ش٠ب اٌم١ٌٔٛٛخ اٌغبئطخ رش١ش فٟ أغٍت اٌظٓ إٌٝ ِغزػ ٜٛبي ِٓ ِغججبد األِشاع فٟ أٛؽاع ا١ٌّبٖ ٘زٖ ٚاٌزٞ ٠غجت ٌٍٕبط اٌز٠ٓ ٠زؼبٍِْٛ ِغ ٘زٖ ا١ٌّبٖ ِخبؽش ط١ؾخ عغ١ّخ.

4 اؽٌٛذاد ا١ؼٌّبس٠خ ٌزشو١ضاد اٌجىزش٠ب اٌم١ٌٔٛٛخ اٌغبئط١خ ؽٚ" ٟ٘ذاد رشى١ً اٌّغزؼّشح" ٌىً 100 ١ٍٍِزش ِٓ ١ػٕخ ا١ٌّبٖ.

5 ٚ٘زا ٠شًّ اٌجشش اٌز٠ٓ ٠زؼشٛػْ ٌألٙٔبس اٌزٟ رؼبٟٔ ِٓ ِغزٜٛ شذ٠ذ ٌٍزٍٛس اٌّّشع )ط< ؽٚ 1000ذح رشى١ً اٌّغزؼّشح / ١ٍِ100ٍزش (. XVI

Buch_UNEP_vordere_Kapitel_1504.indb 16 09.05.16 17:12 Executive Summary

اؾٌب١ٌخ ِبصاٌذ ِغٌٛٙخ ؽزٝ ا٢ْ ٚأؼ٠ب إٌٝ أْ اؽزّبي أْ رىْٛ أػذاد األشخبص اؼٌّشػخ ٌٍخطش وج١شح عذا. ٚال رشًّ ٘زٖ اٌزمذ٠شاد اٌّضاس١ػٓ اؼٌّش١ػٓ ١ٌّبٖ اٌشٞ اٌٍّٛصخ ٚال عىبْ اٌّذْ.

إْ إٌغبء ؼِشػبد ٌٍخطش ثشىً خبص ثغجت اعزخذاِٙٓ اٌّزىشس ١ٌّبٖ األٙٔبس ٚاٌج١ؾشاد ٌزٕظ١ف اٌّالثظ ٚعّغ ا١ٌّبٖ ٌألغشاع إٌّض١ٌخ ِٓ ٚ ٟٙؽششة ٚوزٌه األؽفبي ؼٌجُٙثغجت فٟ ا١ٌّبٖ اٌغط١ؾخ ا١ٍؾٌّخ ٚأؼ٠ب ألُٙٔ ٠زٌْٛٛ غبٌجب ِّٙخ عّغ ا١ٌّبٖ ٌألػّبي إٌّض١ٌخ . .

ِٓ اٌغذ٠ش ثبٌزوش أْ رشو١ض اٌجىز١ش٠ب اٌم١ٌٔٛٛخ اٌغبئط١خ صاد ث١ٓ ػبٚ 1990 ِٟ 2010 فٛؽ ٟاٌٟ صٍضٟ ِغًّ األٙٔبس فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآع١ب. ٚرؼبدي ِغبؽبد األٙٔبس اٌزٟ "ر١ًّ إٌٝ اٌزذٛ٘س ثشىً ِمٍك "ٛؾٔ 6 سثغ ِغّٛع وٍٛ١ِزشاد أٙٔبس ٘زٖ اٌمبساد ١ؽش اسرفؼذ ِغز٠ٛبد اٌجىز١ش٠ب اٌم١ٌٔٛٛخ اٌغبئط١خ فٙ١ب ؽبدإٌٝ ِغزٜٛ أٚ وبٔذ رؼبٟٔ أطال ِٓ ِغزؽ ٛبد فػ ٟبَ 1990 صُ رفبلُ ثٍٛؾي ػبَ .٠ٚ 2010ّىٓ اػزجبس ٘زٖ إٌّبؽك ثؤس إ٘زّبَ سئ١غ١خ فٟ ٘زٖ اٌم١ؼخ . .

٠شعغ عضء وج١ش ِٓ ٘زا اٌزضا٠ذ إٌٝ رٛعغ أٔظّخ اٌظشف اٌظٟؾ اٌزٟ فرظش ا١ٌّبٖ اٌمزسح ثغ١ش ؼِبٌغخ إٌٝ ا١ٌّبٖ اٌغط١ؾخ. ٚثبٌٕظش إٌٝ عبٔت ٚاؽذ، ٛ٘ٚ إرا ِب رُ ٔمً ١ِبٖ اٌظشف اٌظٟؾ ث١ؼذا ػٓ إٌّبؽك اٌّىزظخ ،ثبٌغىبْ فجبٌزبٌٟ عزؾذ اٌّظبسف اٌظ١ؾخ ِٓ اٌّخبؽش اٌظ١ؾخ إٌبعّخ ػٓ اٌشػب٠خ اٌظ١ؾخ غ١ش اٌغ١ٍّخ. ٌٚىٕٙب ِٓ ٔب١ؽخ أخشٜ ٔمٍذ اٌّخبؽش اٌظ١ؾخ إٌٝ ا١ٌّبٖ اٌغط١ؾخ ِٓ خالي إٌمبء ١ِبٖ اٌظشف اٌظٟؾ إٌٝ ا١ٌّبٖ اٌغط١ؾخ ثال ؼِبٌغخ. أشبسدٚ اٌزمذ٠شاد إٌٝ أْ رشو١ض اٌم١ٌٔٛٛبد اٌغبئط١خ اؾٌٍّّخ فػ ٟبَ 2010 إٌٝ األٙٔبس األفش٠م١خ لذ رىْٛ أطغش ثٕغجخ 23 فٟ اٌّبئخ إ ثٕبْ ٌُ ٠زُ ء اٌّظبسف اٌظ١ؾخ . ٌٚىٓ ال ٠ىّٓ اؾًٌ فٟ اؾٌذ ِٓ اٌّظبسفثٕبء اٌظ١ؾخ ثً فؼِ ٟبٌغخ ١ِبٖ اٌظشف اٌظٟؾ اٌّغؼّخ فٙ١ب . .

٠ؤصش اٌزٍٛس اؼٌعٞٛ اٌشذ٠ذ ثبٌفٍٝػ ًؼ وٍٛ١ِزشحٛاٚ ٌٟاحذ ِٓ أصً وً سجؼخ وٍٛ١ِزشاد ِٓ ِجًّ ِسبحبد األٙٔبس فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآس١ب. ٠شىًٚ اسرفبع ِسزٜٛ اٌزٍٛس اؼٌعٛ١ِٚ ٌٞٛٗ ٔحٚ ٛظغ أشذ سٛءا ِصذس لٍك ثخصٛص ص١ذ أسّبن ا١ٌّبٖ اؼٌزثخ ٚثبٌزبٌٟ أ٠عب ثخصٛص رٛف١ش األِٓ اٌغزائٚ ٟظّبْ سجً ا١ؼٌش. اٌفئبدٚرشًّ اٌّزعشسح ِٓ اٌزٍٛس اؼٌعٞٛ سىبْ اٌش٠ف اٌفمشاء ؼ٠زّذْٚاٌز٠ٓ ٍٝػ أسّبن ا١ٌّبٖ اؼٌزثخ وّصذس سئ١سٟ ٌٍجشٚر١ٓ فٟ غزائُٙ وّب رشًّ ص١بدٞ األسّبن ٚاؼٌّبي ر ٞ ٚ اٌذخً إٌّخفط اٌز٠ٓ ؼ٠زّذْٚ ف١ؼِ ٟشزٍٝػ ُٙ ص١ذ أسّبن ا١ٌّبٖ اؼٌزثخ.

٠ٕشأ اٌزٍٛس اؽ ٓػ ٞٛؼؼٌش٠ك رغشة و١ّبد وج١شح ِٓ اٌّشوجبد ا٠ٛؼؼٌخ اٌمبثٍخ ٌٍزؾًٍ فٟ ِغبسٞ اٌغط١ؾخا١ٌّبٖ . ٚوض١شا ِب اؾٔالي٠ؤدٞ ٘زٖ اٌّشوجبد إٌٝ أخفبع خط١ش فٟ ألا ٚوغغ١ٓ اٌّزاة ِظبدسفٟ األٙٔبس ٚاٌزٟ ؼ٠زّذ ٙ١ٍػب األعّبن ٚاٛ١ؾٌأبد اٌّبئ١خ األخشٜ.

رشىً أعّبن ا١ٌّبٖ اٌذاخ١ٍخ عضءا ٘بِب ِٓ اٌجشٚر١ٓ فٟ إٌظبَ اٌغزائٟ ٌغىبْ اٌجٍذاْ إٌب١ِخ. ٍٝػ اٌظ١ؼذ اؼٌبٌّٟ ؼ٠زجش ط١ذ األعّبن اٌذاخ١ٍخ عبدط أُ٘ اٌّظ ب ٌٍجشٚدس ر١ٓ اٛ١ؾٌاٚ ٌٟٔىٓ ط١ذ أعّبن ا١ٌّبٖ اٌذاخ١ٍخ ٠شىً فٟ ثؼغ اٌجٍذاْ إٌب١ِخ أوضش ِٓ 50 فٟ اٌّبئخ ِٓ اٌجشٚر١ٓ اٛ١ؾٌأٟ إٌّزظ ػّٓ رٌه اٌجٍذ.

وّب أْ ط١ذ األعّبن ا١ٍؾٌّخ ؼ٠زجش ِظذسا ٘بِب ٌىغت ا١ؼٌش فٟ اٌجٍذاْ إٌب١ِخ فئٔٗ ٛ٠فش فشص 21 ٛؾٌٕ ًّػ ٛ١ٍِْ ط١بد ٚٛؾٔرٛف١ش 38.5 ٚ ْٛ١ٍِظ١فخ راد طٍخ ثظ١ذ األعّبن فٟ اٌجٍذاْ إٌب١ِخ. ٚرزٛاعذ أغٍت ٘زٖ اٌٛظبئف فٟ اٌّظب٠ذ اٌظغ١شح اٌزٟ أطؾبة٠غبٌجب ِب زٛال٘ب اٌذخً إٌّخفغ ٚاٌزٟ رشىً إٌغبء فٙ١ب أوضش ِٓ ٔظف ِغّٛع اٌمٜٛ اؼٌبٍِخ. ٌزٌه فئْ ِٓ اٌّمٍك أْ ٍٝػ األلً 10٪ ِٓ ع١ّغ اٌم١بعبد فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآع١ب رج١ٓ ِغز٠ٛبد ِمٍمخ ٌضالصخ ؼِب١٠ش ٍٝػ األلً ِٓ أطً خّغخ ١ػٌٕٛخ ا١ٌّبٖ ٚراد األ١ّ٘خ اٌخبطخ ٌغالِخ ط١ذ األعّبن.

أْ اٌزٍٛس اٞٛؼؼٌ اٌشذ٠ذ )١ؽش ٠ض٠ذ رشو١ض اٌطٍت اٌجٌٛٛ١عٟ اٌى١ّ١بئٍٝػ ٟ األوغغ١ٓ ػشٙش٠ب ٍٝ 8 ٍِغ / ٌزش فٟ ر١بس ا١ٌّبٖ( لذ أصش فػ ٟبَ ٛؽ ٍٝػ 2010اٌٟ أعضاءػششعضء ِٓ ح ِغبؽبد أٙٔبس أِش٠ىب اٌالر١ٕ١خ ٍٝػٚ عضء ِٓ عجؼخ أعضاء ِغبؽبد األٙٔبس األفش٠م١خ ٛؾٔ ٍٝػٚ عذط ِغبؽبد األٙٔبس ا٢ع٠ٛ١خ.

ِّٚب ٠ض١ش اٌمٍك أؼ٠ب أْ اٌزٍٛس اٞٛؼؼٌ ) اٌّج١ٓ ؽ ٓػش٠ك اسرفبع رشو١ض اٌطٍت اٌجٌٛٛ١عٟ اٌى١ّ١بئٍٝػ ٟ األوغغ١ٓ فٟ األٙٔبس لذ رفبلُ( ث١ٓ ػبٚ 1990 ِٟ 2010 فٟ لشاثخ صٍضٟ ِغًّ األٙٔبس فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآع١ب. رشىً فئخ ِغبؽبد ٘زٖ األٙٔبس اٌزٟ "ر١ًّ إٌٝ رفبلُ اػٌٛغ ثشىً ِمٍك " عضء ِٓ أطً أعضاءػششح ِغّٛع وٍٛ١ِزشاد أٙٔبس ٘زٖ اٌمبساد ١ؽش

6 ٠مظذ اٌزمش٠ش ثبٌّٕبؽك اٌزٟ " ر١ًّ إٌٝ اٌزذٛ٘س ثشىً ِمٍك " إٌٝ ِٕبؽك رؼبٟٔ ِٓ ِغزٜٛ رٍٛس ٚطً إٌٝ دسعخ اٌزٍٛس اؾٌبد ث١ٓ ػب2010ٚ 2008 ِٟ أٚ وبْ لذ ٚطً أطال إٌٝ ٘زٖ اٌّشؽٍخ فٟ اٌفزشح ث١ٓ ػب1992ٚ 1990 ِٟ صُ اصدادد ؽذرٗ فٟ اٌفزشح ث١ٓ ػب2010ٚ 2008 ِٟ.

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Buch_UNEP_vordere_Kapitel_1504.indb 17 09.05.16 17:12 A Snapshot of the World’s Water Quality: Towards a global assessment | UNEP report

اسرفؼذ ِغز٠ٛبد رشو١ض اٌطٍت اٌجٌٛٛ١عٟ اٌى١ّ١بئٍٝػ ٟ األوغغ١ٓ فٙ١ب ؽبدإٌٝ ِغزٜٛ أٚ وبٔذ رؼبٟٔ أطال ِٓ ِغزؽ ٛبد فػ ٟبَ 1990 صُ اسرفغ ٘زا اٌّغزٜٛ ثٍٛؾي ػبَ ٠ٚ 2010ّىٓ اػزجبس ٘زٖ إٌّبؽك ثؤس اإل٘زّبَ اٌشئ١غ١خ فٟ ٘زٖ اٌم١ؼخ . .

٠ؤصش ا اٌشذ٠ذٌزٍٛس ٚاؼٌّزذي ثبألِالح ثبٌفٍٝػ ًؼ حٛاػ ٌٟ شش ِجًّ ِسبحبد أٙٔبس أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآس١ب. األِش اٌزٞ ٠ض١ش اٌمٍك ألْ ِسز٠ٛبد ػب١ٌخ ِٓ ٠فسذاٌٍّٛحخ اسزخذاَ ١ِبٖ األٙٔبس ٌٍشٚ ٞاٌصٕبػخ ٚغ١ش٘ب ِٓ االسزخذاِبد. رشًّ اٌفئبد اٌّزعشسح ِٓ اٌزٍٛس ثبألِالح اٌّضاس١ػٓ اٌفمشاء اٌز٠ٓ ؼ٠زّذٍٝػ ْٚ ا١ٌّبٖ اٌسطح١خ وّصذس سٞ ساظٙ١ُأل ساظٙ١ُأل .اٌجس١طخ

٠ٕشأ "اٌزٍٛس ثبألِالػ " ػٕذِب ٠شرفغ رشو١ض األِالػ اٌزائجخ ٚاٌّٛاد األخشٜ فٟ األٙٔبس ٚاٌج١ؾشاد إٌٝ دسعخ رؼشلً اعزخذاَ ٘زٖ ا١ٌّبٖ ٚ ٍٝػعٗ ؽغٓ. ٍٝػٚ اٌشغُ ِٓ أْ ؼِظُ األٙٔبس رمش٠جب رؾزٍٝػ ٞٛ ثؼغ األِالػ ثغجت رفزذ األرشاة ٚاٌظخٛس فٟ ِغزغٙؼّبرٙب اٌّبئ١خ ٌىٓ اٌّغزّغ اٌجششٞ عجت فٟ اصد٠بد ٘زٖ اٌّغز٠ٛبد إؽ ٌٝذ وج١ش ثغجت رفش٠غ اٌزذفك اٌّشرذ ٌٍشٞ ٚاؾًٌّّ ثبألِالٚ ػوزٌه اٌفؼالد اٌغبئٍخ إٌّض١ٌخ رظش٠فبدٚ إٌّبعُ وٍٙب فٟ األٙٔبس . .

إْ اٌ ثبألِالػزٍٛس ألً أزشبسا اٌزٍٛسِٓ اٌّّشع أٚ اٌزٍٛس اٞٛؼؼٌ فٟ اٌمبساد اٌزٟ أعش٠ذ دساعخ ٕٙػب . ٍٝػ اٌشغُ ِٓ رٌه ٠ؤصش اٌزٍٛس ثبألِالػ اؼٌّز ٚاٌشذ٠ذذي ع٠ٛب )أ١ؽ ٞش ٠ىْٛ اٌزشو١ض اٌشٙشٞ إلعّبٌٟ اٌّٛاد اٌّزاثخ أوضش ِٓ 450 ٍِغ / ٌزش( ٚ ٍٝػاؽذ ِٓ وً ػشش٠ٓ وٍٛ١ِزشا ِٓ أٙٔبس أِش٠ىب اٌالر١ٕ١خ ٛؽ ٚاػ ٍٝػٌٟ شش ِغبؽبد أٙٔبس ٍٝػٚأفش٠م١ب ٛؽاٌٟ ع جغ ٛؽاٌٟ ع ِغبؽبد أٙٔبس آع١ب. إْ اعزخذاَ األٙٔبس١ِبٖ راد اٌزٍٛس اؼٌّزذي عضئ١ب ؾِذٚد ِغبيفٚ ٟاٌشٞ ال ٠ّىٓ اعزؼّبٌٗ فٟ ثؼغ اٌّغبالد اٌظٕب١ػخ دْٚ رٕم١خ إػبف١خ . ٚلذ ٠ىْٛ اٌّضاسٛػْ اٌفمشاء األوضش رأصشا ألُٙٔ ؼ٠زّذٍٝػ ْٚ ا١ٌّبٖ اٌغط١ؾخ وّظذس ٌشٞ أساٙ١ػُ اٌجغ١طخ . .

ٌ رفبلُمذ اٌزٍٛس ثبألِالػ ث١ٓ ػبٚ 1990 ِٟ 2010 فٟ ِب ٠مشة صٍش إعّبٌٟ األٙٔبس فٟ اٌمبساد اٌضالس. عضء ِٓ ِغبؽبد األٙٔبس ٘زٖ )ٔغجخ طغ١شح ِٓ ِغًّ ِغشٜ األٙٔبس( " ١ّ٠ً ثشىً ِمٍك إٌٝ رفبلُ اػٌٛغ " ١ؽش اسرفؼذ ِغز٠ٛبد إعّبٌٟ اٌّٛاد اٌّزاثخ ف١ٗ إٌٝ ِغزٜٛ خط١ش أٚ وبْ ؼ٠بٟٔ أطال ِٓ ِغزؽ ٛبد فػ ٟبَ 1990 صُ رفبلُ ٘زا اٌّغزٜٛ ثٍٛؾي ػبَ .2010 .2010

رؼذ و١ّخ اٌّٛاد اٌّغز٠خ راد إٌّشأ اٌجششٚ ٞاٌّحٍّخ إٌٝ اٌجح١شاد اٌىجشٜ وج١شح ٠ّٚىٓ أْ رزسجت فٟ اإلصشاء اٌغزائٌٙ ٟزٖ ٌٙزٖ اٌجح١شاد أٚ رض٠ذ ِٓ شذرٙب . ٠ٚخزٍف اٌّسبس اٌّسزمجٍٟ ٘زٌٖ حبٌخ اٌى١ّبد ِغ اخزالف ِٕبغك اؼٌبٌُ.

اإلصشاء اٌغزائٛ٘ ٟ اٌزغ١ّذ اٌّفشؽ ٌٍج١ؾشاد ٚاٌّغطؾبد اٌّبئ١خ األخشٜ ِّب ٠ؤدٞ إٌٝ اخزالي ١ٍّػبرٙب اٌطج١ؼ١خ. ػٚبدح ِب رزغجت و١ّخ اٌفٛعفٛس راد إٌّشأ اٌجششٞ فٟ اإلصشاء اٌغزائٟ ٌألٙٔبس ٌٚىٓ رغزط١غ و١ّبد وج١شح ِٓ ا١ٌٕزشٚع١ٓ أْ رؼٍت دٚسا أْ فٟ رٌه أؼ٠ب. رٕشأ أوضش ِٓ ٔظف ِغّٛع و١ّبد اٌفٛعفٛس ١ػٛٔخاٌّٛ فٟ 23 ِٓ أطً 25 ث١ؾشح وجشػ 7ٜب١ٌّب ِٓ ِظبدس ثشش٠خ. ٚثبإلػبفخ إٌٝ رٌه فئْ ؼِظُ اٌج١ؾشاد اٌىجشٜ فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب رؼبٟٔ ِٓ و١ّبد ِزضا٠ذح فٙ١ب. ٍٝػٚ عج١ً اٌّمبسٔخ فئْ ٘زٖ اٌى١ّبد آخزح فٟ اٌزٕبلض فٟ أِش٠ىب اٌشّب١ٌخ ٚأٚسٚثب ثفؼً اٌٍغٛء إٌٝ إعشاءاد فؼبٌخ ٌخفغ اٌفٛعفٛس.

٠ىّٓ ا اٌشئ١سٌٟسجت ٌزفبلُ رٍٛس ا١ٌّبٖ رح١ًّفٟ ص٠بدح األٙٔبس ٚاٌجح١شاد ثبٌفعالد اٌسبئٍخ ٚ. رخزٍف أُ٘ اٌّصبدس اٌحب١ٌخ ٌٍزٍٛس حست اٌّٛاد اٌٍّٛصخ . اٌىٓ األسجبة ألسبس١خ ٌزٍٛس ا١ٌّبٖ ا فٟرٌّزضا٠ذ ىّٓ إٌّٛ اٌسىبٚ ٟٔص٠بدح إٌشبغ االلزصبدٞ ٚرىض١ف اٌضساػخ ٚرٛسٙؼب ثبإلظبفخ إّٛٔ ٌٝ اٌصشف اٌصحٟ ِغ ػذَ ؼِبٌجخ ا١ٌّبٖ ف١ٗ أؼِ ٚبٌجزٙب ٍٝػ ِسزٛ ظ١ؼف فمػ .

٠مًٍ عّغ اٌّخٍفبد اٌغبئٍخ اٌّظبسففٟ ِٓ رؼشع اٌجشش اٌّجبشش ٌٍٕفب٠بد ِٚغججبد األِشاع ٚرشىً اٌّظبسف ثٙزٖ اٌطش٠مخ اعزشار١غ١خ ٘بِخ ؾٌّب٠خ اٌظؾخ اؼٌبِخ. ٌٚىٓ ِغ رٌه فئْ ثٕبء شجىبد اٌظشف اٌظٟؾ أدٜ إٌٝ رشو١ض سِٟ اٌٍّٛصبد فٟ ا١ٌّبٖ اٌغط١ؾخ ٠ٕٚمً ثزٌه ِٛلغ اٌخطش اٌظٍٝػ ٟؾ إٌبط.

أإْ وجش ِظذس ٌٍزٍٛس اٌّّشع ) و١ّبد ؾٍِّخ ثبٌجىز١ش٠ب اٌم١ٌٔٛٛخ اٌغبئط١خ( فٟ أِش٠ىب اٌالر١ٕ١خ ٛ٘ اٌفؼالد اٌغبئٍخ إٌّض١ٌخ اٌّغؼّخ فٟ اٌّغبسٞ، أِب فٟ فأفش٠م١ب ٛٙ إٌفب٠بد إٌّض١ٌخ اٌغ١ش ِغؼّخ فٟ ِظبسف ٢ع١ب، ٚثبٌٕغجخ فٛٙ اٌفؼالد اٌغبئٍخ إٌّض١ٌخ اٌّغؼّخ فٟ اٌّغبسٞ رٙ١ٍب ِجبششح إٌفب٠بد اٌغ١ش ِغؼّخ فٟ ِظبسف . .

أوجش ِظذس ٌٍزٍٛس اٞٛؼؼٌ )و١ّبد اٌطٍت اٌجٌٛٛ١عٟ اٌى١ّ١بئٍٝػ ٟ األوغغ١ٓ( فٟ أِش٠ىب اٌالر١ٕ١خ ٛ٘ اٌفؼالد اٌغبئٍخ إٌّض١ٌخ اٌّغؼّخ فٟ ،اٌّغبسٞ، أِب فٟ فأفش٠م١ب ٛٙ إٌفب٠بد إٌّض١ٌخ اٌغ١ش ِغؼّخ فٟ ِظبسف ٢ع١ب، ٚثبٌٕغجخ ف ٛٙ اٌفؼالد ٛٙ ف اٌغبئٍخ إٌبرغخ ػٓ اٌمطبع اٌظٕبٟػ.

7 ٠مظذ ٘زا اٌزمش٠ش ة "اٌج١ؾشاد اٌىجشٜ اؼٌب١ٌّخ" اٌج١ؾشاد اٌخّظ اٌىجشٜ ِٓ ٔب١ؽخ ِغبؽخ عطٙؾب فٟ ع١ّغ إٌّبؽك اٌخّظ اٌّذسٚعخ فٟ ِششٚع رٛ لؼبد اٌج١ئخ اؼٌب١ٌّخ ٌجشٔبِظ األُِ اٌّزؾذح ٌٍج١ئخ )UNEP ١ٔٛ٠ت()أفش٠م١ب ٚآع١ب ٚأٚسٚثب ٚأِش٠ىب اٌالر١ٕ١خ ٚأِش٠ىب اٌشّب١ٌخ(.

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Buch_UNEP_vordere_Kapitel_1504.indb 18 09.05.16 17:12 Executive Summary

ؼ٠ٚذ أوجش ِظذس ثششٞ ٌٍزٍٛس ثبألِالػ )اٌى١ّبد اؾٌٍّّخ ثئعّبٌٟ اٌّٛاد اٌّزاثخ( فٟ أِش٠ىب اٌالر١ٕ١خ ٛ٘ اٌمطبع اٌظٕبٟػ أِب فٟ أفش٠م١ب ٚآع١ب فٛٙ اٌضساػخ اٌّش٠ٚخ.

رؼزجش إٌفب٠بد اٛ١ؾٌا١ٔخ ٚاألعّذح غ١ش اٌ ٠ٛؼؼخ ِٓ أُ٘ ِظبدس اٌفٛعفٛس اٌجششٞ إٌّشأ اؾًٌّّ إٌٝ اٌج١ؾشاد اٌىجشٜ فٟ أِش٠ىب اٌالر١ٕ١خ أِب ثبٌٕغجخ ألفش٠م١ب فأُ٘ اٌّظبدس ٟ٘ إٌفب٠بد اٛ١ؾٌا١ٔخ ٚثبٌٕغجخ ٢ع١ب ٚأٚسٚثب ٟ٘ اٌفؼالد اٌغبئٍخ إٌّض١ٌخ ٚإٌفب٠بد اٛ١ؾٌا١ٔخ ٚاألعّذح ٛؼػاٌغ١ش ٠خ ٚثبٌٕغجخ ألِش٠ىب اٌشّب١ٌخ ٟ٘ األ اٌغ١شعّذح ٠ٛؼػخ.

ٍٝػ اٌشغُ ِٓ أْ رٍٛس ا١ٌّبٖ ٠شىً ٚظؼب خط١شا ٠ٚضداد سٛءا فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآس١ب فئْ غبٌج١خ األٙٔبس فٟ ٘زٖ اٌمبساد اٌضالس إال أٔٗ ال ٠ضاي فٟ حبٌخ ج١ذح ٕٚ٘بٌه فشص وج١شح ٌٍحذ ِٓ اٌزٍٛس ثطشق لص١شح اٌّذٜ حبٌخإلٚ صالح األٙٔبس زحراٌزٟ بط حب١ٌب ٌزٌه .

ٌمذ رٛؾّس رشو١ض إٌمبؽ اٌغبثمخ ٍٝػ ِغبؽبد األٙٔبس اٌٛاعؼخ اٌزٟ رؼب١ػٛٔ ِٓ ٟٔخ ١ِبٖ ع١ئخ ٠ٚضداد ٙؼػٚب عٛءا ٌٚىٓ ٍٝػ اٌغبٔت ا٢خش ِبصاي ٕ٘بن سٚافذاؼٌذ٠ذ ِٓ األٙٔبس اٌغ١ش ٍِٛصخ ثؼذ : :

 ِب ٠مشة ِٓ ٔظف إٌٝ صٍضٟ إعّبٌٟ اٌشٚافذ إٌٙش٠خ )فٟ أِش٠ىب اٌالر١ٕ١خ ٚأفش٠م١ب ٚآع١ب( ِغزٜٛ ِٕخفغ ِٓ اٌزٍٛس اٌّّشع  أوضش ِٓ صالصخ أسثبع ٘زٖ األٙٔبس ٌذٙ٠ب ِغزٜٛ ِٕخفغ ِٓ اٌزٍٛس اٞٛؼؼٌ،  ٌذٛؽ ٜاٌٟ رغؼخ أػشبس ِٕٙب ِغزٜٛ ِٕخفغ ِٓ اٌزٍٛس ثبألِالػ . .

ٚال صاٌذ ؽّب٠خ ٘زٖ األٙٔبس إٌظ١فخ ِٓ اٌزٍٛس اٌشذ٠ذ ِّىٕخ . ٚوزٌه ٠ّىٓ أؼ٠ب اعزؼبدح ٔظبفخ اٌشٚافذ إٌٙش٠خ ؽب١ٌباٌٍّٛصخ . ٠ّٚىٓ ارخبر اؼٌذ٠ذ ِٓ اإلعشاءاد ٌزغٕت ص٠بدح اٌزٍٛس ٚ ال ٔظبفخعزؼبدح ا١ٌّبٖ اؼٌزثخ اٌٍّٛصخ:

.1 بلشٌا ثخ – ٕ٘بن ؽبعخ ؾٍِخ ص٠بدحإٌٝ فُٙ شذح اٌزؾذٞ ٌاؼٌب١ػٕٛ ٌّٟخ ا١ٌّبٖ ٚٔطبلٗ . ٚإلدسان ٘زا اٌفُٙ ال ثذ ِٓ رٛع١غ اٌشلبثخ ١ػٛٔ ٍٝػخ ا١ٌّبٖ ال ع١ّب فٟ اٌجٍذاْ إٌب١ِخ ٚثخبطخ ٍٝػ ِغزػ ٜٛبٌّٟ ِٓ خالي النظام العالمي لرصد البيئة/ المياه المعروف باسم GEMS/Water . .2 اٌزمذ٠شاد – ٕ٘بن ؽبعخ ؾٍِخ رمذ٠شادإ١ٍؾِ ٌٝخ ٚد١ٌٚخ شبٍِخ ٛؽي اٌزؾذٞ ٌاؼٌب١ػٕٛ ٌّٟخ ا١ٌّبٖ: رف١ذ ٘زٖ اٌزم١١ّبد قاٌطشفٟ رؾذ٠ذ إٌٝ اٌّٛالغ راد األ٠ٌٛٚخ اٌخبطخ ٚر١١ؼٓ اإلعشاءاد اٌالصِخ ٌٍزؼبًِ ِغ رٍٛس ا١ٌّبٖ. .3 خ١بساد رم١ٕخ إداسٚ ٠خ رم١ٍذ٠خ ؽٚذ٠ضخ – ال رزؼ١ ٌٍذٚي إٌب١ِخ فشص العزخذاَ أعب١ٌت رم١ٍذ٠خ ؼٌّبٌغخ اٌفؼالد اٌغبئٍخ فؾغت، ثً ٌذٙ٠ب أؼ٠ب فشص ٌإلعزفبدح ِٓ اٌىض١ش ِٓ اٌخ١بساد اإل ٚاٌزم١ٕخداس٠خ اؾٌذ٠ضخ إلداسح ١ػٛٔخ ا١ٌّبٖ ثّب فٟ رٌه اٍٛؾٌي اؼٌّزّذح ٍٝػ اٌطجؼ١خ . . .4 إػذاد ِؤعغبد فؼبٌخ – ؼ٠ذ ِٓ أُ٘ إٌمبؽ إلداسح ١ػٛٔخ إٔشبءا١ٌّبٖ رغ١شِؤعغبد إعشاءاد اٌغ١طشح ٍٝػ رٍٛس ا١ٌّبٖ رزغٍتٍٝػ ٚ اٛؼٌائك اٌزٟ رٛؾي دْٚ اٌغ١طشح٘زٖ . .

رؼػٛ ٘زٖ األفىبس فٟ إٌمؾ اٌزب١ٌخ : :

ِب ٠ّىٓ اٌم١بَ ثٗ : أٚال. اٌشلبثخ

ال ٠ّىٓ ٚظغ رم١١ّبد شبٍِخ ١ػٌٕٛخ ا١ٌّبٖ اؼٌب١ٌّخ ثسجت ظؼف رغط١خ ث١بٔبد ١ػٛٔخ ا١ٌّبٖ اٌسطح١خ اٌّسجٍخ فٟ إٌظبَ اؼٌبٌّٟ ٌشصذ اٌج١ئخ / GEMStat رؼزجشٚاٌزٟ لبػذح اٌج١بٔبد اؼٌب١ٌّخ اٌٛح١ذح ١ػٕٛخا١ٕؼٌّخ ث ا١ٌّبٖ.

ؾ٠زٞٛ إٌظبَ اؼٌبٌّٟ ٌشطذ اٌج١ئخ/ ٍٝػ GEMStat وضبفخ ِٕخفؼخ عذا ِمبسٔخ ِغ اٌىضبفبد اٌظغشٜ إٌّط١خ ٌّٕبؽك األٛؽاع إٌٙش٠خ فٟ اٌٛال٠بد اٌّزؾذح ٚأٚسٚثب رؼبديٚاٌزٛؽ ٟاٌٟ 1.5 إؾِ 4 ٌٝطبد فٟ وً 10000 و2ُ. أِب ثبٌٕغجخ ٌمبػذح ث١بٔبد إٌظبَ اؼٌبٌّٟ ٌشطذ اٌج١ئخ/ GEMStat فئْ ِٓ أطً ٛؽ 110ع ِٓ أٛؽاع االٙٔبس راد اٌج١بٔبد ٠ظٙش ػٛؽ 71ب وضبفخ رؼبدي 0.5 ألؾًِطخ أٚ ٌىً 10000 و2ُ.

ٚطً ؼِذي اٌىضبفخ فٟ اٌفزشح اٌض١ِٕخ ث١ٓ ػبٚ 1990 ِٟ 2010 فٟ لبسح أِش٠ىب اٌالر١ٕ١خ إٛؽ ٌٝاٌٟ 0.3 خؾِط ٌىً 10000 10000 وُ ٚ 2فٟ أفش٠م١ب فىبْ 0.02 خؾِط 8 ٌىً 10000 وٚ 2ُأِب فٟ آع١ب فىبْ 0.08 خؾِط ٌىً 10000 و2ُ . .

8 األساٟػ اٌغبفخ غ١ش ؾِغٛثخ ػّٓ إٌّطمخ اٌمبس٠خ.

XIX

Buch_UNEP_vordere_Kapitel_1504.indb 19 09.05.16 17:12 A Snapshot of the World’s Water Quality: Towards a global assessment | UNEP report

شعغر األ٠ٌٛٚخ اٌمظٜٛ ١عإٌٝ اٌزٛ غ اٌضٚ ِٟٕاٌّىبٟٔ ٌٕطبق رغط١خ ؾِطبد اٌّشالجخ ٚرٌه ثذال ِٓ ص٠بدح ػذد اؼٌٍّّبد اٌزٟ ٠زُ عٙؼّب فٟ اؾٌّطبد ١ػٛٔخاؽ ٌّٛب١ٌب . ٔظشاٚ اٌزىبإٌٝ ٌٍّش١ٌف اؼٌب١ٌخ ٠ٕجغٟالجخ ػٚغ أ٠ٌٛٚبد رؾذد األٙٔبس راد اٌج١بٔبد إٌبلظخ اٌزٟ ٠ٕجغٟ سطذ٘ب أٚال. ٠ّٚىٓ اعزخذاَ ثؤس اإل٘زّبَ اٌّ ؼشفخ فٟ ٘زا اٌزمش٠ش وّذخالد ٌزؾذ٠ذ إٌّبؽك اٌزٟ ٠ٕجغٟ أْ ٠ ىضف فٙ١ب اٌشطذعٛٙد . .

ٛؼ٠د ظؼف رغط١خ اٌج١بٔبد ألسجبة س١بس١خ ِٚؤسس١خ ٚرم١ٕخ ٌٚىٓ ٠جمٝ ٕ٘بن اؼٌذ٠ذ ِٓ اٌجذائً ٌزحس١ٓ رغط١خ اٌج١بٔبد حٛي ١ػٛٔخ ا١ٌّبٖ.

إؽذٜ ٘زٖ اٌجذائً ٌزؾغ١ٓ اٌزغط١خ ٠ّضً االعزفبدح ِٓ ث١بٔبد االعزشؼبس ػٓ ثؼذ . ٚرغطٟ ِغػّٛبد اٌج١بٔبد اؾٌب١ٌخ اٌّزغ١شاد ٌاٌشئ١غ١خ ١ػٕٛخ ١ِبٖ ا ٌٚج١ؾشاد فٟ اٌّغزمجً اٌمش٠ت عٛف رظجؼ اٌج١بٔبد ِزبؽخ ٌألٙٔبس أؼ٠ب . ٠ٚزّضً ١ِضح االعزشؼبس ػٓ ثؼذ فٟ اٌزغط١خ اٌّىب١ٔخ ٚاٌضِب١ٔخ اٌٛاعؼخ ٌٍج١بٔبد؛ ٠ٚىّٓ ٛ١ػثٙب اؾٌّذٚفٟ اؼٌذد ٌٍّزغ١شادد اٌزٟ ٠ّىٕٗ ل١بعٙب ٚفؼِ ٟبٌغخ اٍٛؼٌِّبد األ٠ٌٛٚخ اٌّطٍٛثخ . .

رشًّ اإلِىب١ٔبد األخشٜ ٌزؾغ١ٓ رغط١خ ث١بٔبد ١ػٛٔخ ٍٟ٠ا١ٌّبٖ ِب 1: ) ( رشغ١غ اٌغٛٙد اٌشا١ِخ إٌٝ إدساط اٌج١بٔبد ا١ٕؽٌٛخ ٚاإلل١ّ١ٍخ فٟ لٛاػذ اٌج١بٔبد ا١ػٌّٛٔٛخ ؽب١ٌب 2) ( إٔشبء فشق ١ٕؽٚ ًّػخ ٌشطذ ا١ٌّبٖ اؼٌزثخ رؼًّ ِغ ٔظشائٙب فٟ اٌجٍذاْ األخشٜ رمبعٍٝػُ َاعزخذاٚ ث١بٔبد ١ػٛٔخ ا١ٌّبٖ )3( اعزشعبع اٌج١بٔبد ِٓ خالي ِشبس٠غ ِزؼٍمخ ثؼٍُ اٌّٛاٚ .ٓؽرزّضً ا١ٌّضح اإلػبف١خ ؼٌٍُ اٌّٛاؽٓ فٟ إششان عّٛٙس أٚعغ فٟ رٕظ١ف ا١ٌّبٖ اٌٍّٛصخ . .

٠ٕجغٟ أؼ٠ب أْ رغٝؼ عٛٙد عّغ اٌج١بٔبد ٌغٍٙؼب ِزبؽخ ٍٝػ ٔطبق ٚاعغ ٚلبثٍخ ٌإلعزشعبع ؽ ٓػش٠ك ِٕظخ سل١ّخ ِضً إٌّجش اٌزفبٍٟػ ٌجشٔبِظ األُِ اٌّزؾذح ٌٍج١ئخ. ٚ ٠ٕجغٟ أْ رىْٛ اٌج١بٔبد ِزبؽخ ٍٝػ ٔطبق ٚاعغ أؼ٠ب ٠خضف١ّب سطذ أ٘ذاف اٌز١ّٕخ اٌّغزذاِخ ٚرٕف١ز٘ب . .

ِب ٠ّىٓ اٌم١بَ ثٗ: صب١ٔب. اٌزم١ ّبد١

ؾ٠زبط رمذ٠ش اػٌٛغ اؼٌّشفٟ ٌغ١ّغ اٌغٛأت اؾٌغبعخ ثخظٛص ١ػٛٔخ ا١ٌّبٖ إٌٝ رم١١ُ شبًِ إٌطبق ١ػٌٕٛخ ا١ٌّبٖ اؼٌب١ٌّخ، ٚرٌه ػٌٛغ سٚاثؾ ث١ٓ ١ػٛٔخ ا١ٌّبٖ ٚ أخشٜلؼب٠ب ٌٍز١ّٕخ رخض فزشح ِب ثؼذ ػبَ 2015 ِضً اٌظؾخ ٚاألِٓ اٌغزائٚ ٟوزٌه ٚ ٌزؾذ٠ذ اٌغٛأت راد األ٠ٌٛٚخ اٌمظٜٛ ٌذساعزٙب ٚرطج١مٙب . .

٠غت أْ ٠ىْٛ اٌزم١١ُ : :

 ِزؼذد اٌّغز٠ٛبد - ِغ رغط١خ ػب١ٌّخ ِشرجطب ثزم١١ّبد ١ٕؽٚخ بٛػٌّٛعثِزؼٍمخ . .  شفبف ٚرشبسوٟ - ٠شًّ ِغػّٛخ ٚاعؼخ ِٓ أطؾبة اٌّظؾٍخ ٚاؼٌٍّبء . .

٠ٕٚجغٟ أْ ؾ٠زٞٛ اٌزم١١ُ ٍٝػ ِب ٍٟ٠ : :

 األ٘ذاف ٚاٌّٛا١ػغ اٌزٟ رُ رؾذ٠ذ٘ب ثشىً ِشزشن ِٓ لجً اٌّغزؼّبد اٌغ١بعبر١خ ا١ٍّؼٌخٚ . .  ٌٍخ١بر١ٍؾً اٌغ١بعساد بر١خ اٌٙبدفخ ؾٌّب٠خ ١ػٛٔخ ا١ٌّبٖ ٚاعزؼبدرٙب . .  ر١غ١ش إٌزبئظ ٍٝػ شىً ٚاعغ ؽ ٓػش٠ك إربؽزٙب ٍٝػ إٌّظبد اٌشل١ّخ اٌغذ٠ذح )ِضً: إٌّجش اٌزفبٍٟػ ٌجشٔبِظ األُِ اٌّزؾذح ٌٍج١ئخ .( .(

٠ٕجغٟ أؼ٠ب اإلعزفبدح ِٓ اٌزم١١ُ وفشطخ ٌض٠بدح اٌمذساد اٌزم١ٕخ ٌٍجٍذاْ إٌب١ِخ ٚرشغ١غ ٚطٌٙٛب إٌٝ أؽذس إٌزبئظ ا١ٍّؼٌخ.

ِب ٠ّىٓ اٌم١بَ ثٗ :صبٌضب. اإلداسح ٚاٌ اٌف١ٕخخ١بساد

٠زٛفش اؼٌذ٠ذ ِٓ اٌخ١بساد ٌٍجٍذاْ إٌب١ِخ ٌزجٕت رذٛ٘س ١ػٛٔخ ١ِبٖ األٙٔبس ٚاٌجح١شاد. لجً ػمٛد ِعذ وبْ اٌىض١ش ِٓ ٘زٖ وبْ اٌىض١ش اٌخ١بساد غ١ش ِزٛفش ا ِسزخذِبأٚ فٟ اٌذٚي اٌّزمذِخ ػٕذِب ٚاجٙذ ثذٚس٘ب رذٛ٘س ِّبصال ٌ ١ػٕٛخا ا١ٌّبٖ .

رزّضً اٌخ١بساد اٌف١ٕخ اٌشئ١غ١خ فٟ : :

1) ( ِٕغ اٌزٍٛس ؽ ٓػش٠ك رغٕت ِظذس رٍٛس ا١ٌّبٖ لجً أْ ٠زٛؾي إٌٝ ِشىٍخ . .

(ؼِ (2بٌغخ ا١ٌّبٖ اٌٍّٛصخ ٛ٘ٚ إٌٙظ اٌزم١ٍذٞ ٌزم١ًٍ و١ّبد اٌٍّٛصبد لجً رفش٠غٙب فٟ ا١ٌّبٖ اٌغط١ؾخ.

Buch_UNEP_vordere_Kapitel_1504.indb 20 09.05.16 17:12 Executive Summary

3) ( االعزخذاَ ا٢ِٓ ١ٌّبٖ اٌّغبسٚ ٞإػبدح رذ٠ٚش٘ب العزخذاِٙب فٟ اٌشٚ ٞغ١شٖ ِٓ االعزخذاِبد . .

(4) "اٍٛؾٌي اٌزٟ رؼزّذ ٍٝػ اٌطجؼ١خ" ٚاٌزٟ رؼّٓ إطالػ إٌظُ ٠زٙبؽّٚباٌج١ئ١خ ِضً إػبدح إٔشبء اٌغبثبد فٟ ِٕبؽك اٌّغزغؼّبد ثٙذف اؾٌذ ِٓ أغشاف اٌزشثخ ِٚٓ ر١ّؾً اٌشٚاعت إٌٝ األٙٔبس أٚ اعزؼبدح إٌّبؽك اٌشؽجخ إلصاٌخ اٌٍّٛصبد ِٓ رذفمبد ا١ٌّبٖ فٟ إٌّبؽك اؼؾٌش٠خ أٚ اٌضسا١ػخ . .

ٚٔغذ فٟ إؽبس ٘زٖ اٌجٕٛد اؼٌذ٠ذ ِٓ األفىبس اٌغذ٠ذح اٌزٟ ٌُ رىٓ ِزبؽخ ٌٍجٍذاْ اٌّزمذِخ ػٕذِب ٚاعٙذ ألٚي ِشح رذٛ٘سا ِّبصال ١ػٌٕٛخ ا١ٌّبٖ ِٕز صالصخ ػمٛد أٚ أوضش. ِٚٓ ث١ٓ ٘زٖ األفىبس اٌغذ٠ذح: اإلٔزبط األٔظف فٟ اٌظٕبػخ، األساٟػ اٌشؽجخ اٌزٟ رُ إٔشبئٙب، و١ٍبٚاٌزخٍض ِٓ رظش٠ف اٌفؼالد اٌغبئٍخ، ٚاٌّذفػٛبد ِمبثً ُخذِبد إٌظ اٌج١ئ١خ ٌّٕبثغ األٙٔبس اٌّشغشح . .

ٕ٘بن حبجخ السزشار١ج١بد رم١ٕخ ِخزٍفخ ٌٍس١طشح ٍٝػ األٛٔاع اٌّخزٍفخ ِٓ رٍٛس ا١ٌّبٖ ِٚصبدس٘ب. ِٚٓ اٌّف١ذ اخزجبس ٘زٖ االسزشار١ج١بد ٚرجٙؼ١ّب إٌٝ حضَ ٠ّىٓ رطج١مٙب ٍٝػ اؼٌذ٠ذ ِٓ أحٛاض األٙٔبس اٌّخزٍفخ.

ِٚٓ ٔب١ؽخ أخشؽٚ ،ٜغجّب أششٔب فأػالٖ ، أْ اٌّظبدس اٌشئ١غ١خ ٌٍزٍٛس رخزٍف ِغ اخزالف أٛٔاع رٍٛس ا١ٌّبٖ. ٚ٘زا ٟٕؼ٠ أْ فىشح "ٚ ًؽاؽذ ٠ٕبعت اٌغ١ّغ" ٌٓ رٕغؼ فؽ ًٟ ِشىٍخ اٌزؾذٞ اؼٌب١ػٌٕٛ ٌّٟخ ا١ٌّبٖ. ٌٚىٓ ِٓ ٔب١ؽخ أخشٜ فئْ رؾذ٠بد ِّبصٍخ ١ػٌٕٛخ رمغا١ٌّبٖ فٟ ع١ّغ أؾٔبء اؼٌبٌُ ٚرٌه سغُ االخزالف اٌشذ٠ذ ٌٍّٛالغ ٚاألػٚبع فٙ١ب فمذ. ٌزٌه ٠ىْٛ ِٓ اٌّّىٓ رط٠ٛش ؽضَ رشًّ إِىب١ٔبد رم١ٕخ الِخزٍفخ عزخذاِٙب فٟ اؼٌذ٠ذ ِٓ أٛؽاع األٙٔبس اٌّزػٕٛخ ٌٍزؼبًِ ِغ ِشبوً ِّبصٍخ.

ِب ٠ّىٓ اٌم١بَ ثٗ :ساثؼب. اإلداسح اٌّؤسسبدٚ

أشبسد دساسبد حبالد ػٓ أحٛاض أٙٔبس ِخزٍفخ إٌٝ أ١ّ٘خ اإلداسح اٌشش١ذح ٚفؼب١ٌخ اٌّؤسسبد إلداسح ١ػٛٔخ ا١ٌّبٖ.

ٌ أُ٘مذ رج١ٓ أْ اٛؼٌائك دْٚاٌزٟ رٛؾي اٌزغٍت ٍٝػ ِشبوً رٍٛس ا١ٌّبٖ رشًّ ِب ٍٟ٠ : :

 أمغبَ اٌغٍطخ ػّٓ ِٕطمخ ٛؽع ٙٔش ١ؼِٓ،  ٔمض فٟ ،اٌمذساد اٌزم١ٕخ ٚ  اٌشأٞلٍخ ٟػٚ اؼٌبَ ٛؽي أعجبة رٍٛس ا١ٌّبٖ.

ٌٍٚزغٍت ٍٝػ ٘زٖ اٛؼٌائك ٚغ١ش٘ب اٌخجشحأظٙشد ِٓ دساعبد اؾٌبالد ؽٍّخأْ اٌز١ػٛخ اؼٌبِخ ٟ٘ ِم١بط أٚي ع١ذ ٌىغت اٌذػُ فٟ ِىبفؾخ رٍٛس ا١ٌّبٖ. وّب ث١ٕذ ٘زٖ اٌخجشح أْ خطخ اؼًٌّ اٌّزفك ٙ١ٍػب ِٓ ل جً ع١ّغ اٌغٙبد اٌفبػٍخ اٌشئ١غ١خ ٛؾٌع إٌٙش ٟ٘ خطٛح سئ١غ١خ إلطالػ األٙٔبس ٚاٌج١ؾشاد. ٚوزٌه ٠شىً إٔشبء ١٘ئبد رؼب١ٔٚخ خطٛح رأع١غخ سئ١غ١خ أخشٜ ٌألٙٔبس اٌذ١ٌٚخ وّب ٛ٘ اؾٌبي ٌٍغبْ اٌذ١ٌٚخ ٙٔ ٍٝػشٞ اإلٌجٗ ٚفٌٛزب اٌزٟ رٙذف إػٚ ٌٝغ خطخ ٚ ًّػرٕف١ز٘ب . ٚثبٌٕغجخ إٙٔ ٌٝش اإلٌجٗ فمذ رج١ٓ أؼ٠ب أْ ِؤعغخ ١ٕؽٚخ ٚاعؼخ إٌطبق )ِٕظِٛخ ٛؽع ٙٔش اإلٌجٗ( رغزط١غ أْ رٛفش ِٕجشا ل١ّب ٌىغت رؼبْٚ ع١ّغ اٌغٙبد اٌفبػٍخ ا١ٕؽٌٛخ األعبع١خ ٌّٕطمخ ٛؽع إٌٙش.

٠شرجِٛ ػاجٙخ اٌزحذٞ اؼٌب١ػٌٕٛ ٌّٟخ ا١ٌّبٖ اسرجبغب ٚص١مب ثؼذح أ جزّب١ػخا٠ٌٛٚبد أخشٜ ِضً األِٓ اٌغزائٚ ٟاٌصحخ. ٌٙٚزا رٕع٠ُجت أْ اإلجشاءاد اٌالصِخ ٌحّب٠خ ١ػٛٔخ ا١ٌّبٖ فٟ ِششٚع االسزذاِخ األٚسغ ٚوزٌه ٠جت أْ رىْٛ جضءا ِٓ اٌجٛٙد اٌشا١ِخ إٌٝ رحم١ك اأ٘ذاف ٌز١ّٕخ اٌّسزذاِخ اٌجذ٠ذح.

أظٙشد دساعبد اؾٌبالد أْ اٌزؾذٞ اٌّزّضً فؽ ّٟب٠خ ١ػٛٔخ ٠زشبا١ٌّبٖ ثه ِغ اؼٌذ٠ذ ِٓ اٌّٙبَ عزّب١ػخاال األخشٜ - رٛف١ش اٌغزاء ٚر١ّٕخ االلزظبد ٚرٛف١ش خذِبد اٌظشف اٌظٟؾ ا٢ِٕخ. ٌٚزٌه ع١ىْٛ ِٓ اٌُّٙ عذا ٍٝػ ِذٜ اٌغٕٛاد اٌمبدِخ سثؾ أ٘ذاف ١ػٛٔخ ا١ٌّبٖ ِغ األ٘ذاف األخشٜ ٌغذٚي أػّبي ِب ثؼذ ػبَ ٚ 2015وزٌه سثطٗ أ٘ذافِغ اٌز١ّٕخ اٌّغزذاِخ اٌغذ٠ذح.

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Executive Summary

Main messages

• Good water quality, together with an adequate quantity of water, are necessary for achieving the Sustainable Development Goals for health, food security and water security. Therefore it is of concern that water pollution has worsened since the 1990s in the majority of rivers in Latin America, Africa and Asia. • It is important that actions to protect and restore water quality are linked to efforts to achieve the Sustainable Development Goals and the Post 2015 Development Agenda. • Severe pathogen pollution already affects around one-third of all river stretches in Latin America, Africa and Asia. In addition to the health risk of drinking contaminated water, many people are also at risk of disease by coming into contact with polluted surface waters for bathing, clothes cleaning and other household activities. The number of rural people at risk in this way may range into the hundreds of millions on these continents. • Severe organic pollution already affects around one-seventh of all river stretches in Latin America, Africa and Asia and is of concern to the state of the freshwater fishery and therefore to food security and livelihoods. • Severe and moderate salinity pollution affects around one-tenth of all river stretches in Latin America, Africa and Asia and is of concern because it impairs the use of river water for irrigation, industry and other uses. • The immediate cause of increasing water pollution is the growth in wastewater loadings to rivers and lakes. Ultimate causes are population growth, increased economic activity, intensification and expansion of agriculture, and increased sewerage hook-ups with no or a low level of treatment. • Among the groups most vulnerable to water quality deterioration in developing countries are women because of their frequent usage of surface water for household activities, children because of their play activities in local surface waters and because they often have the task of collecting water for the household, low income rural people who consume fish as an important source of protein, and low income fishers and fishery workers who rely on the freshwater fishery for their livelihood. • Although water pollution is serious and getting worse in Latin America, Africa, and Asia, the majority of rivers on these three continents are still in good condition, and there are great opportunities for short-cutting further pollution and restoring the rivers that are polluted. A mix of management and technical options supported by good governance will be needed for these tasks. • A wide range of management and technical options are available to developing countries for water pollution control. Many of these options were not available or used by developed countries when confronted with similarly deteriorating water quality decades ago. • Monitoring and assessment of water quality are essential for understanding the intensity and scope of the global water quality challenge. Yet the coverage of data in many parts of the world is inadequate for this purpose. For example, the density of water quality measuring stations in Africa is one hundred times lower than the density used elsewhere in the world for monitoring. An urgent task is therefore to expand the collection, distribution, and analysis of water quality data through the international GEMS/Water Programme and other activities. Hot spot areas of water pollution identified in this report can be used to set priorities for data collection.

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People and ecosystems require both an adequate quantity of water as well as an adequate quality of water. Therefore, it is urgent to assess where water quality is inadequate or under threat and to incorporate the need for good water quality into the concept of water security. This report focuses on water quality and its relation to development objectives such as health, food security and water security. To make this connection, the report reviews important water quality problems in surface waters including pathogen pollution, organic pollution, salinity pollution and eutrophication. The focus is on three continents: Latin America, Africa, and Asia. Enhancing water security has been an international priority for the last several years. Through Millennium Development Goals and other efforts, the international community has given priority to the quantity side of water security by expanding the access of people to a safe water supply. Indeed, delivering an adequate amount of water to people, to industry, and to agriculture is, and should remain, a high international priority. But another dimension of water security is becoming increasingly important – ensuring that freshwaters have an adequate quality of water. This is of concern because the water quality of the world’s rivers and lakes is going through important changes. The growing priority being given to water quality is reflected in various targets in the Sustainable Development Goals. Water quality has markedly improved in many developed countries, although some problems persist. Meanwhile, in developing countries the tendency is towards increasing water pollution as urban populations grow, material consumption increases and untreated wastewater volumes expand. But the actual situation of water quality in freshwater ecosystems in much of the world can only be conjectured because of the lack of basic information. Therefore, an assessment is urgently needed to identify the scope and scale of the “global water quality challenge”. This pre-study aims to provide some of the building blocks for a full-scale world water quality assessment that can be scaled up to a full assessment. It also presents a preliminary estimate of the water quality situation of freshwater ecosystems in the world, with an accent on rivers and lakes on three continents. Water pollution has worsened since the 1990s in the majority of rivers in Latin America, Africa, and Asia.1 Changes between 1990 and 2010 in key parameters in rivers reflecting pathogen pollution (faecal coliform bacteria), organic pollution (biochemical oxygen demand; BOD), and salinity pollution (total dissolved solids; TDS) have been estimated. The level of pathogen pollution and organic pollution worsened in more than 50 per cent of river stretches on all three continents, while salinity pollution worsened in nearly a third2. The worsening is of particular concern in a subset of these river stretches where water pollution has increased to a severe level, or was already at a severe level in 1990 and had worsened by 2010. Severe pathogen pollution3 already affects around one-third of all river stretches in Latin America, Africa and Asia. The number of rural people at risk to health by coming into contact with polluted surface waters may range into the hundreds of millions on these continents. Among the most vulnerable groups are women and children. Severe pathogen pollution (where monthly in-stream concentrations of faecal coliform bacteria are >1000 cfu/100ml4) is estimated to affect around a quarter of Latin American river stretches, around 10 to 25 per cent of African river stretches and about a third to one-half of Asian river stretches. Hence, of the three continents, the extent of pathogen pollution appears to be greatest in Asia. Taking into account the fraction of rural population that is likely to come into contact with surface waters5 it is estimated that approximately 8 to 25 million people are at risk in Latin America, 32 to 164 million in Africa and 31 to 134 million in Asia. The wide range of these estimates shows that there are still many unknowns about the actual risk, but also that the numbers of people at risk are likely to be very large. These estimates do not include farmers exposed to contaminated irrigation water, nor people living in cities.

1In this report the following UNEP “Global Environmental Outlook” sub-regions are used to define “Latin America”, “Africa”, and “Asia”: Latin America = Central America, South America, Caribbean; Africa = Central Africa, Eastern Africa, Northern Africa, Southern Africa, Western Africa, Western Indian Ocean; Asia = Central Asia, North East Asia, South Asia, South East Asia, West Asia region (Arabian Peninsula, Mashriq) 2In this summary, rounded figures are used for the results of analyses. It is appropriate to present rounded results considering the uncertainties of the underlying estimates. The main text presents these underlying estimates. This includes people coming into contact with rivers that have a severe level of pathogen pollution (x > 1000 cfu/100ml) 3A severe level of pathogen pollution is defined in Footnote 5. Such water bodies are likely to have a level of pathogens as indicated by a high level of faecal coliform bacteria, implying that people coming into contact with these waters are exposed to a high health risk. 4The standard units of fecal coliform concentrations are “colony-forming units” (cfu) per 100 ml of water sample. 5This includes people coming into contact with rivers that have a severe level of pathogen pollution (x > 1000 cfu/100ml)

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At particular risk are women because of their frequent usage of water from rivers and lakes for cleaning clothes and collecting water for cooking and drinking in the household, and children because of their play activities in local surface waters and also because they often have the task of collecting water for the household. It is worth noting that concentrations of faecal coliform bacteria have increased between 1990 and 2010in almost two-thirds of all rivers in Latin America, Africa and Asia. The river stretches with an “increasing trend of particular concern”6 amount to about one-quarter of the total kilometres of rivers in these continents where faecal coliform bacteria levels increased to a severe level, or were at a severe level in 1990 and worsened by 2010. These can be considered hot spot areas. A large fraction of the increase is due to the expansion of sewer systems that discharge wastewater untreated into surface waters. On one hand, by taking the wastewater away from populated areas, the sewers have reduced the health risk posed by unsafe sanitation practices on land. On the other hand, by dumping sewage untreated into surface waters, they have transferred the health risk from the land to surface waters. It was estimated that if sewers had not been built, fecal coliform loadings into African rivers in 2010 might have been 23 per cent smaller. The solution, however, is not to build fewer sewers, but to treat the wastewater they collect. Severe organic pollution already affects around one out of every seven kilometres of all river stretches in Latin America, Africa and Asia. The high level of organic pollution and its increasing trend is of concern to the state of the freshwater fishery and therefore to food security and livelihoods. Groups affected by organic pollution include poor rural people that rely on freshwater fish as a main source of protein in their diet and low income fishers and workers who rely on the freshwater fishery for their livelihood. Organic pollution is caused by the release of large quantities of decomposable organic compounds into surface water bodies. The breakdown of these compounds often leads to a serious reduction in the dissolved oxygen resources of a river relied upon by fish and other aquatic fauna. Fish from inland waters make up an important part of the protein in the diet of people in developing countries. Globally, the inland fishery is the sixth most important source of animal protein, but in some developing countries the catch of inland fish accounts for more than 50 per cent of the animal protein produced within that country. Inland capture fisheries are also an important source of livelihood in developing countries. Inland fisheries in developing countries provide employment for 21 million fishers and 38.5 million related jobs. Almost all of these were in small scale fisheries, occupied by mostly low income people, with over half of the total workforce being women. It is therefore disquieting that at least 10% of all measurements from Latin America, Africa, and Asia show levels of concern for at least three out of five water quality parameters of particular importance to the health of fisheries. In 2010, severe organic pollution (where monthly in-stream concentrations of BOD are > 8 mg/l) is estimated to affect up to around one-tenth of Latin American river stretches, up to about one-seventh of African river stretches, and up to about one-sixth of Asian river stretches. It is also of concern that organic pollution (as indicated by increasing river concentrations of BOD) has increased between 1990 and 2010 in almost two-thirds of all rivers in Latin America, Africa and Asia. A subset of these river stretches with an “increasing trend of particular concern” amount to about one-tenth of the total kilometres of rivers in these continents where BOD levels increased to a severe level, or were at a severe level in 1990 and worsened by 2010. These can be considered hot spot areas. Severe and moderate salinity pollution already affects around one-tenth of all river stretches in Latin America, Africa and Asia and is of concern because high salinity levels impair the use of river water for irrigation, industry and other uses. Groups affected by salinity pollution include poor farmers that rely on surface waters as a source of irrigation water for their small holdings. “Salinity pollution” occurs when the concentration of dissolved salts and other substances in rivers and lakes is high enough to interfere with the use of these waters. Although almost all rivers have some salt content because of weathering of soils and rock in their drainage basin, society has greatly increased these levels by discharging salt-laden irrigation return flows, domestic wastewater and runoff from mines into rivers.

6“Increasing trend of particular concern” in this report means a pollution level that increased into the severe pollution category in 2008–2010, or was already in the severe pollution category in 1990-1992 and further increased in concentration by 2008–2010. XXX

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Saline pollution is less widespread than pathogen or organic pollution on the continents studied. Nevertheless, moderate and severe salinity pollution together (i.e., where monthly in-stream concentrations of TDS are > 450 mg/l) affect one out of every twenty kilometres of rivers in Latin America, up to about one-tenth of river stretches in Africa, and up to about one-seventh of river stretches in Asia. River water in the moderate pollution category is partly restricted for use in irrigation, and cannot be used for some industrial applications without further purification. Particularly affected may be poor farmers who rely on surface waters as a supply of irrigation water for their small holdings. Salinity pollution has increased between 1990 and 2010 in almost one-third of all rivers on the three continents. A subset of these river stretches (a few percent of all river reaches) have an “increasing trend of particular concern” in which TDS levels increased to a severe level, or were at a severe level in 1990 and worsened by 2010. Anthropogenic loads of nutrients to major lakes are significant and may cause or further advance eutrophication of these lakes. The trends of these loads are different in different parts of the world. Eutrophication is the over-fertilisation of lakes and other water bodies which leads to a disruption of their natural processes. Lake eutrophication is usually caused by anthropogenic loads of phosphorus, but loads of nitrogen can also play a role. More than half of the total phosphorus loads in 23 out of 25 major lakes7 worldwide are from anthropogenic sources. In addition, most of the major lakes in Latin America and Africa have increasing loads. By comparison, loads are decreasing in North America and Europe because of effective phosphorus-reducing measures. The immediate cause of increasing water pollution is the growth in wastewater loadings to rivers and lakes. The most important current sources of pollution vary from pollutant to pollutant. Ultimate causes of growing water pollution are population growth, increased economic activity, intensification and expansion of agriculture, and increased sewerage with no or low level of treatment. Collecting wastewater in sewers reduces the direct contact of people with wastes and pathogens and in this way is an important strategy for protecting public health. However, building sewers has also concentrated the discharge of pollutants into surface waters and shifted the location of health risk to people. The largest source of pathogen pollution (loadings of faecal coliform bacteria) in Latin America is domestic wastewater from sewers, for Africa it is non-sewered domestic waste, and for Asia it is domestic wastewater from sewers followed closely by non-sewered domestic waste. The largest source of organic pollution (BOD loadings) in Latin America is domestic wastewater from sewers, for Africa it is non-sewered domestic waste, and for Asia it is wastewater from the industrial sector. The largest anthropogenic source of salinity pollution (loadings of TDS) in Latin America is industry, and in Africa and Asia it is irrigated agriculture. Important sources of anthropogenic phosphorus to major lakes in Latin America are livestock wastes and inorganic fertiliser, in Africa livestock wastes, in Asia and Europe domestic wastewater, livestock wastes and inorganic fertiliser, and in North America inorganic fertiliser. Although water pollution is serious and getting worse in Latin America, Africa, and Asia, the majority of rivers on these three continents are still in good condition, and there are great opportunities for short-cutting further pollution and restoring the rivers that need to be restored. In previous points the focus was on the extensive reaches of rivers where water quality is poor and further deteriorating. But the other side of the coin is that many stretches of rivers are not yet polluted: • About one half to two-thirds of all river reaches (in Latin America, Africa and Asia) have a low level of pathogen pollution • More than three-quarters have a low level of organic pollution, and • About nine-tenths have low salinity pollution. It is still possible to prevent these clean river reaches from becoming heavily polluted. It is also possible to begin restoring the river reaches that are already polluted. Many actions can be taken to avoid the increase in pollution and restore polluted freshwaters:

7In this report “major world lakes” means the five largest lakes in terms of lake surface area in each of five UNEP “Global Environmental Outlook” regions (Africa, Asia, Europe, Latin America, and North America). XXXI

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1. Monitoring – More understanding is needed about the intensity and scope of the global water quality challenge. For this understanding, it is urgent to expand the monitoring of water quality, especially in developing countries, and especially at the international level through GEMS/Water. 2. Assessments – Comprehensive national and international assessments of the global water quality challenge are needed. These assessments are needed for pointing the way to priority locations and actions for dealing with water pollution. 3. New and old management and technical options – Developing countries have an opportunity to not only employ traditional wastewater treatment, but also to draw on many more new management and technical options for managing water quality including nature-based solutions. 4. Setting upffective e institutions – An essential part of managing water quality is setting up institutions that promote action and overcome barriers to controlling water pollution. These ideas are elaborated in the following points: What can be done: I. Monitoring Comprehensive assessments of global water quality are not possible because of the poor coverage of water quality data of surface waters in GEMStat, the only global water quality data base. GEMStat has a very low density of stations as compared to typical minimum densities of around 1.5 to 4 stations per 10,000 km2 of river basin area in the USA and Europe. In GEMStat, 71 out of the 110 river basins with data have a density of 0.5 stations per 10,000 km² or less. The average density for the Latin American continent is 0.3 stations per 10,000 km², for Africa 0.02 stations8 per 10,000 km², and for Asia 0.08 stations per 10,000 km² for the time period between 1990 and 2010. The highest priority is to expand the temporal and spatial coverage of monitoring stations rather than increase the number of parameters collected at existing stations. Considering the high costs of monitoring it is important to set priorities on which data-deficient rivers should be monitored first. The hot spot areas identified in this report can be used as input in deciding where to expand monitoring efforts. The reasons for poor data coverage are political, institutional, and technical. But there are many alternatives for improving coverage of water quality data. One alternative for improving coverage is to make use of remote sensing data. Current data sets cover key water quality variables for lakes, and in the near future data will become available for rivers. An advantage of remote sensing is the extensive spatial and temporal coverage of the data; disadvantages include the limited number of variables that can be measured and the processing of raw data that is required. Other options for improving coverage of water quality data are: (i) increasing efforts to incorporate national and regional data into existing databases, (ii) establishing national freshwater monitoring working groups to work with their counterparts in other countries on sharing and using water quality data, (iii) retrieving data through citizen science projects. Citizen science has the added advantage of engaging a wider public in cleaning up water pollution. Data collection efforts should also strive to make these data widely available and retrievable through a digital platform such as “UNEP Live”. Data should also be made widely available in connection with the monitoring and implementation of the Sustainable Development Goals. What can be done: II. Assessment A full scale World Water Quality Assessment is needed to assess the state of knowledge about all critical aspects of water quality, to make linkages between water quality and other Post 2015 Development issues such as health and food security, and to identify priority areas for study and actions. The assessment should be: • Multi-level – with global coverage linked to national assessments and thematic assessments. • Transparent and participatory – involving a wide range of stakeholders and scientists.

8Dryland areas are not included in the continental area.

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The assessment should include: • Objectives and themes that are jointly selected by the policy and science communities. • An analysis of policy options for protecting and restoring water quality. • Wide access to results by making them available on new digital platforms (e.g. “UNEP Live”). • The assessment should also be used as an opportunity to increase the technical capacity of developing countries and their access to the latest scientific results. What can be done: III. Management and Technical Options There are many options available to developing countries for avoiding the water quality deterioration of their rivers and lakes. Many of these options were not available or used by developed countries when confronted with similarly deteriorating water quality decades ago. The main technical options are: (i) Pollution prevention in which the source of water pollution is avoided before it becomes a problem. (ii) Treatment of polluted water which is the traditional approach to reducing the loading of pollutants before they are discharged into surface waters. (iii) The safe use of wastewater recycling it for irrigation and other uses. (iv) “Nature-based solutions” involving the restoration and protection of ecosystems, such as re-establishing woodlands in catchments in order to reduce erosion and sediment loadings to rivers or restoring wetlands to remove pollutants from urban or agricultural runoff. Under these headings there are many new ideas that were not available to developed countries when they first confronted similarly deteriorating water quality three or more decades ago. Among these new ideas are:cleaner production in industry, constructed wetlands, zero effluent discharges, and payment for ecosystem services of forested headwaters. Different technical strategies will be needed to control the diverse types of water pollution and sources of pollution. It is worthwhile to try and cluster these strategies into packages that can be applied to many different river basins. On one hand, it was noted above that the main sources of pollution differ between the different kinds of water pollution. This means that a “one size fits all” option will not work to solve the global water quality challenge. On the other hand, similar water quality challenges are occurring around the world even if the locations and situations are very different. Therefore, it may be possible to develop different packages of technical options that can be used in many different river basins to deal with similar problems. What can be done: IV. Governance and Institutions Case studies of different river basins pointed out the importance of good governance and effective institutions for managing water quality. It was found that important barriers to coping with water pollution problems include: • Fragmentation of authority within a river basin, • Lack of technical capacity, and • Lack of awareness on behalf of the public about the causes of water pollution. To overcome these and other barriers, experience from the case studies showed that a public education campaign is a good first measure for gaining support for water pollution control. Another lesson is that an Action Plan, agreed upon by all the main actors in a river basin, is a key step in restoring rivers and lakes. Yet another key institutional step for international rivers is to set up acollaborative body such as the international commissions on the Elbe and Volta rivers for developing and carrying out an action plan. In the case of the Elbe, it was also shown that a wide-reaching national institution (the Elbe River Basin Community) can provide a valuable platform for gaining the cooperation of all critical national actors within a river basin.

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Coping with the global water quality challenge is closely connected to many other priorities of society such as food security and health. Therefore, actions to protect water quality should be embedded in the larger concept of sustainability, and be part of efforts to achieve the new Sustainable Development Goals. The case studies showed that the challenge of protecting water quality is intertwined with many other tasks of society – providing food, developing the economy, and providing safe sanitation. Therefore, over the coming years it will be very important to link goals for water quality with other goals of the Post 2015 Agenda and the new Sustainable Development Goals.

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Résumé analytique

Messages clefs

• La bonne qualité de l’eau, en quantité suffisante, est nécessaires afin de réaliser les objectifs de développement durable incluent des objectifs de santé, de sécurité alimentaire et hydrique. Il est en conséquence préoccupant que la pollution de l’eau se soit aggravée depuis les années 1990 dans la majorité des fleuves d’Amérique Latine, d’Afrique et d’Asie. • Il est d’importance que des mesures pour protéger et restaurer la qualité de l’eau soient liées aux efforts pour réaliser les objectifs de développement durable et le programme de développement durable de l’après 2015. • Plusieurs pollutions pathologiques affectent d’ores et déjà environ un tiers de toutes les étendues fluviales en Amérique Latine, Afrique et Asie. En plus du risque sanitaire que constitue le fait de boire de l’eau contaminée, de nombreuses populations encourent des risques de maladies en entrant en contact avec des eaux de surface polluées pour se baigner, nettoyer leurs vêtements et d’autres activités ménagères. Le nombre de populations rurales exposées à des risques de cet ordre peut atteindre plusieurs centaines de millions sur ces continents. • Une pollution organique grave affecte d’ores et déjà environ un septième de toutes les étendues fluviales en Amérique Latine, Afrique et Asie et constitue un sujet de préoccupation pour l’état des ressources de pêche en eau douce et en conséquence pour la sécurité alimentaire et les moyens de subsistance. • Des pollutions salines graves et modérées affectent environ un dixième de toutes les étendues fluviales en Amérique Latine, Afrique et Asie et constituent un sujet de préoccupation car faisant obstacle à l’utilisation de l’eau des fleuves pour l’irrigation, l’industrie et d’autres usages. • La cause immédiate d’augmentation de la pollution des eaux est la croissance des charges d’eaux usées dans les fleuves et les lacs. Les causes premières sont constituées de la croissance démographique, l’activité économique accrue, l’intensification et l’expansion de l’agriculture et les branchements de systèmes d’égouts sans aucun ou avec un faible niveau de traitement. • Les femmes font partie des groupes les plus vulnérables à la détérioration de la qualité des eaux dans les pays en développement du fait de leur usage fréquent des eaux de surface pour les activités ménagères, les enfants du fait de leurs activités de jeux dans les eaux de surface locales et parce qu’ils ont souvent la tâche de collecter l’eau pour le foyer, les populations rurales à faible revenu qui consomment du poisson comme source importante de protéine, et les pêcheurs et travailleurs de la pêche à faible revenu qui dépendent de la pêche en eau douce pour leur subsistance. • Bien que la pollution de l’eau soit importante et s’aggrave en Amérique Latine, Afrique et Asie, la majorité des fleuves sur ces trois continents est encore en bon état et il existe des possibilités de limiter rapidement une pollution supplémentaire et de restaurer les fleuves pollués. Une combinaison de gestion et d’options techniques soutenue par une bonne gouvernance sera nécessaire pour réaliser ces tâches. • Un large éventail d’options de gestion et d’options techniques est à disposition des paysen développement pour le contrôle de la pollution des eaux. Nombre de ces options n’étaient pas disponibles ou utilisées par les pays développés lorsqu’ils ont été confrontés il y a plusieurs décennies à une détérioration similaire de la qualité des eaux. • La surveillance et l’évaluation de la qualité des eaux sont indispensables à la compréhension de l’intensité et de l’étendue du défi mondial de la qualité des eaux. Pourtant, la couverture des

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données dans de nombreuses parties du monde n’est pas adéquate. Par exemple, la densité des stations de mesure de la qualité de l’eau en Afrique est cent fois plus faible que la densité des stations de surveillance ailleurs dans le monde. Une tâche urgente est en conséquence d’accroître la collection, distribution et l’analyse de données relative à la qualité des eaux via le programme international de surveillance GEMS/Water et d’autres activités. Les zones sensibles de pollution des eaux identifiées dans ce rapport peuvent être utilisées pour fixer les priorités de la collection des données.

Les populations, tout comme les écosystèmes ont besoin d’une quantité suffisante ainsi que d’une qualité optimale de l’eau. En conséquence, il est urgent d’évaluer les endroits où la qualité de l’eau est insuffisante ou menacée et d’incorporer le besoin d’une bonne qualité des eaux dans le concept général de sécurité hydrique. Ce rapport se concentre sur la qualité des eaux et sur son lien avec les objectifs de développement tels que la santé, la sécurité alimentaire et la sécurité hydrique. Afin d’établir ce lien, le rapport passe en revue des problèmes significatifs de la qualité de l’eau dans les eaux de surface telle que la pollution pathogène, la pollution organique, la pollution saline et l’eutrophisation. Le rapport se concentre sur trois continents: l’Amérique latine, l’Afrique et l’Asie. Améliorer la sécurité hydrique a constitué une priorité internationale au cours des dernières années. Avec les Objectifs du Millénaire et d’autres efforts, la communauté internationale a donné la priorité à l’aspectquantitatif de la sécurité hydrique en augmentant l’accès des populations à une source d’eau sûre. En effet, faire en sorte que les populations, l’industrie et l’agriculture aient accès à unequantité adéquate d’eau est et devrait demeurer une priorité internationale élevée. Mais une autre dimension de la sécurité hydrique est en train de gagner en signification – garantir que les eaux douces possèdent une qualité suffisante d’eau. Ce point est préoccupant car la qualité des eaux des fleuves et lacs du monde subit d’importants changements. La priorité donnée à la qualité de l’eau se reflète dans différentes cibles des objectifs du développement durable. La qualité de l’eau s’est améliorée sensiblement dans plusieurs pays développés, malgré la persistance de plusieurs problèmes. En même temps, dans les pays en développement, la tendance est à l’augmentation de la pollution des eaux tandis que les populations urbaines croissent, que la consommation matérielle augmente et que les volumes d’eaux usées non-traitées augmentent. Mais la situation réelle de la qualité des eaux dans des écosystèmes d’eau douce dans la majorité des régions du monde peut seulement faire l’objet d’hypothèses du fait du manque d’informations de base. En conséquence, une évaluation est nécessaire de manière urgente afin d’identifier l’étendue et la portée du « défi mondial de la qualité de l’eau ». Cette pré-étude vise à fournir quelques-uns des éléments nécessaires à une évaluation mondiale à grande échelle de la qualité de l’eau qui puisse être transformée en une évaluation complète. Elle présente également une estimation préliminaire de la situation de la qualité de l’eau des écosystèmes d’eau douce, en mettant l’accent sur les fleuves et lacs de trois continents. La pollution de l’eau s’est aggravée depuis les années 1990 dans la majorité des fleuves d’Amérique latine, d’Afrique et d’Asie1. Les changements survenus entre 1990 et 2010 ont été évalués selon les paramètres clefs des fleuves. Ces changements reflètent la pollution pathogène (bactérie coliforme fécale), la pollution organique (demande biochimique en oxygène, DBO) et la pollution saline (total de solides dissous, TDS). Le niveau de la pollution pathogène et de la pollution organique a augmenté dans plus de 50 % des étendues fluviales sur lestrois continents, tandis que la pollution saline s’est aggravée dans environ un tiers d’entre elles2. Cette détérioration est particulièrement préoccupante dans un sous-ensemble de ces étendues fluviales où la pollution de l’eau a augmenté jusqu’à un niveau alarmant ou présentait déjà un niveau élevé en 1990 et s’était aggravé entre 1990 et 2010.

1Dans ce rapport, les sous-régions du « Global Environment Outlook » du PNUD sont utilisées pour définir « l’Amérique latine », « l’Afrique » et « l’Asie »: Amérique Latine = Amérique centrale, Amérique du sud, Caraïbes; Afrique = Afrique centrale, Afrique de l’est, Afrique du nord, Afrique du sud, Afrique de l’ouest, Océan indien de l’ouest; Asie = Asie centrale, Asie du nord-est, Asie du sud, Asie du sud-est, région de l’Asie de l’ouest (péninsule arabique, Machreq) Afrique = Afrique centrale, Afrique de l’est, Afrique du nord, Afrique du sud, Afrique de l’ouest, Océan indien de l’ouest ; Asie = Asie centrale, Asie du nord-est, Asie du sud, Asie du sud-est, région de l’Asie de l’ouest (péninsule arabique, Machreq) XXXVI 2Dans ce résumé, des chiffres arrondis sont utilisés pour indiquer les résultats des analyses. Considérant les incertitudes des estimations sous-jacentes, présenter des chiffres arrondis est approprié. Le texte principal présente ces estimations sous-jacentes.

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Une pollution pathogène grave3 affecte d’ores et déjà environ un tiers de toutes les étendues fluviales d’Amérique Latine, d’Afrique et d’Asie. Le nombre de populations rurales exposées à des risques sanitaires par contact avec des eaux de surfaces polluées peut atteindre des centaines de millions de personnes sur ces continents. Les femmes et les enfants comptent parmi les groupes les plus vulnérables. On estime qu’une pollution pathogène grave (dans laquelle les concentrations mensuelles dans les cours d’eau de bactéries coliformes fécales sont > à 1000 ufc/100ml4) affecte environ un quart des étendues fluviales d’Amérique Latine, environ 10 à 25 pourcent des étendues fluviales africaines et environ un tiers jusqu’à la moitié des étendues fluviales asiatiques. Ainsi, pour les trois continents, c’est en Asie que l’étendue de la pollution pathogène semble être la plus forte. En prenant en compte la proportion de la population rurale à même d’entrer en contact avec les eaux de surfaces5, on estime qu’approximativement 8 à 25 millions de personnes sont exposées au risque en Amérique Latine, 32 à 164 millions en Afrique et 31 à 134 millions en Asie. Le grand éventail de ces estimations montre que de nombreuses inconnues persistent sur le risque réel, et que les nombres de personnes exposées au risque est susceptible d’être très élevé. Ces estimations n’incluent ni les agriculteurs exposés aux eaux d’irrigation contaminées, ni les populations urbaines. Les femmes sont particulièrement exposées au risque car elles utilisent fréquemment des eaux des fleuves et des lacs pour le nettoyage des vêtements, ainsi que pour la cuisine et l’alimentation en eau potable du foyer. Les enfants sont également particulièrement exposés au risque du fait de leurs activités ludiques dans les eaux de surfaces locales et de la tâche qui leur revient souvent de collecter l’eau pour le foyer. Il est significatif de noter que les concentrations de bactéries coliformes fécales ont augmenté entre 1990 et 2010 dans presque deux tiers de tous les fleuves d’Amérique Latine, Afrique et Asie. Les étendues fluviales présentant une « tendance à l’augmentation particulièrement préoccupante6 » représentent environ un quart de la totalité des kilomètres des fleuves sur ces continents où les bactéries coliformes fécales ont augmenté jusqu’à un niveau grave ou étaient à un niveau grave en 1990 et qui a empiré d’ici à 2010. Ces zones peuvent être considérées comme des zones sensibles. Une part importante de l’augmentation est due à l’accroissement des systèmes d’égout qui déchargent les eaux usées non-traitées dans les eaux de surface. D’une part, en éliminant les eaux usées des zones peuplées, les systèmes d’égout ont réduit le risque sanitaire posé par des pratiques d’évacuation dangereuses sur la terre ferme. D’autre part, en évacuant les déchets non-traités dans les eaux de surface, ils ont transféré le risque sanitaire depuis la terre ferme jusqu’aux eaux de surface. Il a été estimé que si les systèmes d’égouts n’avaient pas été construits, les charges de coliformes fécaux dans les fleuves africains en 2010 auraient pu être moindre de 23 %. Cependant, la solution ne consiste pas à construire moins d’égouts mais à traiter les eaux usées qu’ils collectent. Une pollution organique grave affecte d’ores et déjà environ un kilomètre sur sept de toutes les étendues fluviales en Amérique Latine, Afrique et Asie. Le haut niveau de pollution organique et sa tendance à l’augmentation constituent un sujet de préoccupation pour l’état des activités de pêche en eau douce et pour la sécurité alimentaire et les moyens de subsistance. Les groupes affectés par la pollution organique comprennent les populations rurales pauvres qui dépendent des poissons d’eau douce comme source principale de protéines de leur régime alimentaire et les pêcheurs et travailleurs à faible revenu qui dépendent des activités de pêche en eau douce pour leur subsistance. La pollution organique est causée par le rejet de larges quantités de composés organiques décomposables dans les plans d’eaux de surface. La décomposition de ces éléments conduit souvent à une grave réduction des ressources en oxygènes, alors dissoutes, d’un fleuve dont dépendent poissons et faune aquatique. Les poissons des eaux intérieures constituent une part importante des protéines dans le régime alimentaire des populations des pays en développement. De façon générale, la pêche dans les eaux intérieures est la sixième source de protéines animales la plus importante, mais dans certains pays en développement, la proportion des poissons des eaux intérieures compte pour plus de 50 % des protéines animales produites à l’intérieur du pays. Les activités de pêche de capture à l’intérieur des terres sont également un moyen de subsistance majeur dans les pays en développement. La pêche à l’intérieur des terres fournit du travail à 21 millions de pêcheurs et fournit

3Un niveau de pollution pathogène grave est défini à la note de bas de page 5. De tels plans d’eau sont susceptibles d’avoir un niveau de pathogènes tel qu’indiqué par un haut niveau de bactéries coliformes fécales, impliquant que les populations entrant en contact avec des eaux sont exposées à un risque sanitaire élevé. 4L’unité standard des concentrations de coliformes fécales est l’ « unité formant colonie » (ufc) pour 100 ml d’échantillon d’eau. 5En incluant les populations entrant en contact avec les fleuves ayant un niveau grave de pollution pathogène (x > 1000 ufc/100 ml) 6Une « tendance à l’augmentation particulièrement préoccupante » dans ce rapport signifie un niveau de pollution qui a augmenté jusqu’à atteindre la catégorie XXXVII de pollution grave en 2008–2010 ou qui était déjà das la catégorie de pollution grave en 1990–92 et dont la concentration a augmenté d’ici à 2008–2010.

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38,5 millions d’emplois se rapportant à la pêche. Presque tous prennent place dans des activités de pêche à petite échelle et sont occupés en majeure partie par des populations à bas revenu, les femmes constituant plus de la moitié de la force totale de travail. Il est en conséquence inquiétant qu’au moins 10% de toutes les mesures effectuées en Amérique latine, en Afrique et en Asie montrent des niveaux préoccupants pour au moins trois des cinq paramètres de qualité de l’eau qui sont d’importance particulière pour la santé des pêcheurs. En 2010, on a estimé que la pollution organique grave (marquée par des concentrations mensuelles dans le cours d’eau de DBO > 8 mg/l) affecte jusqu’à environ un dixième des étendues fluviales d’Amérique latine, jusqu’à environ un septième des étendues fluviales africaines et jusqu’à environ un sixième des étendues fluviales asiatiques. Il est également préoccupant que la pollution organique (telle qu’indiquée par une concentration en augmentation des concentrations de DBO dans les fleuves) ait augmenté entre 1990 et 2010 dans presque deux tiers de tous les fleuves et toutes les rivières d’Amérique latine, Afrique et Asie. Un sous-ensemble de ces étendues fluviales présentant une « tendance à l’augmentation particulièrement préoccupante » compte jusqu’à environ un dixième de la totalité des kilomètres de fleuves dans ces continents où les niveaux de DBO ont augmenté jusqu’à un niveau grave ou étaient à un niveau grave en 1990 et qui a empiré d’ici à 2010. Ces zones peuvent être considérées comme des zones sensibles. Des pollutions salines graves et modérées affectent d’ores et déjà environ un dixième de toutes les étendues fluviales en Amérique latine, Afrique et Asie et est préoccupante car de hauts niveaux de salinité dégradent l’utilisation des eaux fluviales pour l’irrigation, l’industrie et d’autres usages. Les groupes affectés parla pollution saline comprennent les fermiers pauvres qui dépendent des eaux de surface comme source d’eau d’irrigation pour leurs petites propriétés. La « pollution saline » apparaît lorsque la concentration en sels dissous et autres substances dans les fleuves et les lacs est assez élevée pour empêcher les usages habituels de ces eaux. Bien que presque tous les fleuves possèdent des teneurs en sel en raison de l’usure des sols et des roches dans leur bassin de drainage, les sociétés ont largement augmenté ces teneurs en sel en déchargeant des flux de retour d’irrigation chargés en sel, des eaux usées domestiques et des déchets miniers dans les fleuves. La pollution saline est moins répandue que la pollution pathogène ou organique sur les continents étudiés. Néanmoins, la combinaison d’une pollution saline modérée et d’une pollution saline sévère (c.à.d. marquée par des concentrations mensuelles dans le cours d’eau de TSD > 450 mg/l) affectent un kilomètre survingt d’étendues fluviales en Amérique latine, jusqu’à environ un dixième des étendues fluviales en Afrique et jusqu’à environ un septième des étendues fluviales en Asie. Les eaux fluviales dans la catégorie de pollution modérée sont partiellement restreintes pour l’utilisation comme eaux d’irrigation et ne peuvent être utilisées pour des applications industrielles sans purification supplémentaire. Les fermiers pauvres qui dépendent deseauxde surface comme source d’eaux d’irrigation pour leurs petites propriétés peuvent être particulièrement touchés. La pollution saline a augmenté entre 1990 et 2010 dans presque un tiers de tous les fleuves sur les trois continents. Un sous-ensemble de ces étendues fluviales (un petit pourcentage de tous les cours d’eau) présente une« tendance à l’augmentation particulièrement préoccupante » dans laquelle les niveaux de TSD ont augmenté jusqu’à un niveau élevé ou avait atteint un niveau important en 1990 et se sont aggravés entre 1990 et 2010. Des charges de substances nutritives d’origine anthropique dans les grands lacs sont significatives et peuvent causer ou accélérer une l’eutrophisation de ces lacs. Les tendances de ces charges sont différentes dans différents endroits du monde. L’eutrophisation est la sur-fertilisation de lacs et d’autres étendues d’eau, ce qui conduit à une perturbation de leurs processus naturels. L’eutrophisation des lacs est habituellement causée par des charges d’origine anthropique de phosphore, mais des charges d’azote peuvent également jouer un rôle. Plus de la moitié de ces charges totales de phosphore dans 23 sur 25 grands lacs7 à l’échelle mondiale proviennent de sources anthropiques. En sus, la plupart des grands lacs d’Amérique latine et d’Afrique présentent des charges en augmentation. En comparaison, les charges en Amérique du nord et en Europe décroissent du fait de mesures efficaces de réduction du phosphore.

7Dans ce rapport, « des grands lacs mondiaux » signifient les cinq plus grands lacs en terme de surface du lac dans chacune des cinq régions du « Global Environment Outlook » du PNUD (Afrique, Asie, Europe, Amérique latine et Amérique du nord). XXXVIII

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La cause immédiate d’augmentation de la pollution des eaux est la croissance de la charge en eaux usées des fleuves et des lacs. Les plus importantes sources actuelles de pollution varient selon les polluants. Les causes premières de la pollution croissante des eaux sont la croissance démographique, l’activité économique accrue, l’intensification et l’expansion de l’agriculture et le plus grand nombre de systèmes d’égouts accrus sans ou avec un faible niveau de traitement. La collecte des eaux usées par les égouts réduit le contact direct des populations avec les déchets et les pathogènes et constitue en ce sens une stratégie importante pour la protection de la santé publique. Cependant, la construction d’égouts a également concentré la décharge de polluants dans les eaux de surface et déplacé la location des risques sanitaires pour les populations. La plus importante source de pollution pathogène (charge de bactéries coliforme fécales) en Amérique latine est constituée des eaux usées domestiques des systèmes d’égouts. En Afrique, ce sont les déchets domestiques non évacués par les égouts. En Asie, ce sont les eaux usées domestiques des systèmes d’égouts, suivies de près par les déchets domestiques non évacués. La source de pollution organique la plus importante (charge en DBO) en Amérique latine est constituée des eaux usées domestiques des systèmes d’égouts. En Afrique, ce sont les déchets domestiques non évacués par les égouts. En Asie, ce sont les eaux usées industrielles. La plus importante source anthropique de pollution saline (charge en TSD) en Amérique latine est constituée par l’industrie, et en Afrique et en Asie par l’agriculture irriguée. D’importantes sources de phosphore anthropiques dans les lacs principaux d’Amérique latine sont les déchets issus du bétail et les engrais inorganiques. En Afrique ce sont les déchets issus du bétail. En Asie et en Europe ce sont les eaux usées domestiques, les déchets issus du bétail et les engrais inorganiques, et en Amérique du nord les engrais inorganiques. Bien que la pollution des eaux soit grave et s’aggrave en Amérique latine, Afrique et Asie, la majorité des fleuves sur ces trois continents est encore en bon état et il existe des solutions pour réduire plus rapidement la pollution et restaurer les fleuves qui en ont besoin. Les points précédents se focalisaient sur les parties des fleuves présentant une qualité réduite des eaux se dégradant. Mais l’autre aspect de cette situation est que de nombreuses étendues fluviales ne sont pas encore polluées: • Entre la moitié et les deux-tiers de tous les fleuves (en Amérique latine, Afrique et Asie) présentent un faible niveau de pollution pathogène • Plus des trois quart présentent un faible niveau de pollution organique et • Environ neuf dixièmes présentent un faible niveau de pollution saline. Il est encore possible de faire en sorte que ces étendues fluviales propres ne deviennent pas lourdement polluées. Il est également possible de commencer à restaurer les fleuves qui sont déjà pollués. De nombreuses mesures peuvent être prises pour éviter l’augmentation de la pollution et restaurer les eaux douces polluées. 1. Surveillance – Une compréhension accrue de l’intensité et de l’étendue du défi mondial de la qualité de l’eau est nécessaire. Pour faciliter cette compréhension, il est urgent d’étendre la surveillance de la qualité de l’eau, notamment dans les pays en développement ainsi qu’au niveau international via le programme GEMS/ Water. 2. Evaluation – Des évaluations globales nationales et internationales du défi mondial de la qualité de l’eau sont nécessaires. Ces évaluations sont nécessaires pour déterminer les emplacements prioritaires et les mesures pour lutter contre la pollution des eaux. 3. Gestion ancienneet nouvelle et options techniques – Les pays en développement ont la possibilité de ne pas recourir seulement au traitement traditionnel des eaux usées, mais également de recourir à de nombreuses autres options de gestion et techniques pour gérer la qualité des eaux, y compris des solutions basées sur la nature.

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4. Etablir des institutions efficaces – Un aspect majeur de la gestion de la qualité des eaux réside dans l’établissement d’institutions qui promeuvent l’action et dépassent les obstacles au contrôle de la pollution des eaux. Ces idées sont développées dans les points suivants: Ce qui peut être fait: I Surveillance Des évaluations complètes de la qualité des eaux au niveau mondial ne sont pas possibles du faitdela couverture limitée des données de la qualité des eaux pour les eaux de surfaces dans la seule base de données de la qualité des eaux à l’échelle mondiale, GEMStat. GEMStat a une très faible densité de stations, en comparaison avec des densités minimales typiques d’environ 1,5 à 4 stations pour 10.000 km2 de bassin fluvial aux Etats-Unis et en Europe. Dans GEMStat, 71 des 110 bassins fluviaux sur lesquels des données existent, ont une densité de 0,5 stations pour 10.000 km2 ou moins. La densité moyenne pour le continent d’Amérique latine est de 0,3 stations pour 10.0002 km , pour l’Afrique elle est de 0,02 stations8 pour 10.000 km2, et pour l’Asie de 0,08 stations pour 10.000 km2 pour la période comprise entre 1990 et 2010. La priorité la plus urgente est d’étendre la couverture temporelle et spatiale des stations de surveillance plutôt que d’augmenter le nombre de paramètres collectés par les stations existantes. En considérant les coûts élevés de la surveillance, il importe de fixer des priorités pour les fleuves dont les données disponibles sont faibles, ils devraient faire en premier l’objet d’une surveillance. Les zones sensibles identifiées dans ce rapport peuvent être utilisées comme point d’appui pour décider des endroits où accroître les efforts de surveillance. Les raisons de la faible couverture en données sont politiques, institutionnelles et techniques. Cependant, il existe de nombreuses possibilités pour une amélioration de la couverture en données de la qualité des eaux. Une alternative à l’amélioration de la couverture est de faire usage de données de télédétection. Les séries de données actuelles couvrent des variables clefs de la qualité des eaux pour les lacs, et, dans l’avenir proche, des données seront également disponibles pour les fleuves. L’un des avantages des données sensorielles éloignées est la couverture spatiale et temporelle étendue des données. Les inconvénients incluent le nombre limité de variables pouvant être mesuré ainsi que le traitement nécessaire des données brutes. D’autres options pour l’amélioration de la couverture des données de la qualité des eaux sont: (i) l’augmentation les efforts pour incorporer les données nationales et régionales dans les bases de données existantes, (ii) la formation de groupes de travail pour la surveillance des eaux douces nationales qui travaillent avecleurs interlocuteurs équivalents dans les autres pays pour le partage et l’utilisation des données sur la qualité des eaux, (iii) la récupération de données via des projets de science citoyenne. La science citoyenne a l’avantage d’engager un public plus large pour le nettoyage de la pollution des eaux. Les efforts de collection des données devraient également tendre à rendre ces données largement disponibles et récupérables via une plate-forme digitale telle que UNEP Live. Les données devraient aussi être rendues largement disponibles en lien avec la surveillance et la mise en œuvre des objectifs du développement durable. Ce qui peut être fait: II. Evaluation Une évaluation de la qualité de l’eau à échelle mondiale complète est nécessaire pour évaluer l’étatdes connaissances sur tous les aspects essentiels de la qualité des eaux, afin d’établir des connections entre la qualité des eaux et d’autres enjeux de l’agenda de développement post 2015 tels que la sécurité sanitaire et alimentaire, et pour identifier des zones prioritaires pour l’étude et la prise de mesures. L’évaluation devrait être: • A plusieurs niveaux – avec une couverture mondiale, liée à des évaluations nationales et thématiques. • Transparente et participative – impliquant un large nombre d’acteurs et de scientifiques. L’évaluation devrait inclure: • Des objectifs et des sujets sélectionnés enommun c par les communautés politiques et scientifiques. • Une analyse des options politiques pour la protection et la restauration de la qualité des eaux.

8Les zones arides ne sont pas incluses dans la zone continentale.

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• Un accès large aux résultats en les rendant accessibles sur de nouvelles plates-formes numériques (p.ex. UNEP Live). L’évaluation devrait également être utilisée comme opportunité pour augmenter la capacité technique des pays en développement ainsi que leur accès aux résultats scientifiques les plus récents. Ce qui peut être fait: III. Options de gestion et techniques De nombreuses options sont à disposition des pays en développement afin d’éviter la dégradation de la qualité des eaux de leurs fleuves et lacs. Nombre de ces options n’étaient pas disponibles ou utilisées par les pays développés lorsqu’ils ont été confrontés il y a plusieurs décennies à une similaire dégradation de la qualité des eaux. Les options techniques principales sont: i. La prévention de la pollution par laquelle la source de la pollution est évitée avant qu’elle ne devienne un problème. ii. Le traitement des eaux polluées, ce qui constitue l’approche traditionnelle par la réduction de la charge de polluants avant qu’ils ne soient déchargés dans les eaux de surface. iii. L’usage sûr des eaux usées par leur recyclage en vue de l’irrigation ou d’autres usages. iv. « Des solutions basées sur la nature », impliquant la restauration et la protection des écosystèmes, telles que la réintroduction de terres boisées afin de réduire l’érosion et les charges de sédiments dans les fleuves, ou la restauration de zones humides pour retirer les éléments polluants des écoulements urbains et agricoles. Ces points listent de nombreuses idées nouvelles qui n’étaient pas à disposition des pays développés faisant face à une détérioration similaire de la qualité des eaux il y a trois décennies ou plus. Parmi ces nouvelles idées, on compte: une production industrielle plus propre, l’établissement de zones humides, des décharges à zéro effluent, et le paiement pour les services des écosystèmes des eaux d’amont boisées. Différentes stratégies techniques seront nécessaires pour contrôler les différents types de pollution des eaux et les sources de pollution. Cela vaut la peine d’essayer et de combiner ces stratégies en systèmes qui peuvent être appliqués à de nombreux bassins fluviaux différents. D’une part, il a été noté ci-dessus que la principale source de pollution diffère entre les différents types de pollution des eaux. Ceci signifie qu’une option unique ne fonctionnera pas pour résoudre le défi mondial de la qualité des eaux. D’autre part, des défis de la qualité des eaux semblables apparaissent dans différents endroits du monde, même si les locations et les situations sont très différentes. En conséquence, il peut être possible de développer des systèmes différents d’options techniques qui peuvent être utilisées dans de nombreux bassins fluviaux différents pour affronter des problèmes similaires. Ce qui peut être fait: IV-Gouvernance et institutions Des études de cas des différents bassins fluviaux ont souligné l’importance de la bonne gouvernance et d’institutions efficaces pour la gestion de la qualité des eaux. On compte des obstacles importants à la résolution des problèmes de pollution des eaux: • La fragmentation de l’autorité sur un bassin fluvial, • Le manque de capacités techniques et • Le manque de sensibilisation de la part du public concernant les ausesc de la pollution des eaux. Pour surmonter ces obstacles, l’expérience acquise par les études de cas a montré qu’une campagne d’éducation publique constitue une première bonne mesure pour le contrôle de la pollution des eaux. Une autre leçon est qu’un Plan d’action, convenu par tous les acteurs principaux d’un bassin fluvial constitue une mesure clef dans la restauration des rivières et des lacs. Cependant, une autre mesure institutionnelle clef pour les fleuves internationaux est d’établir un organisme de coopération, telles que les commissions internationales des fleuves de l’Elbe et de la Volta, afin de développer et d’exécuter un plan d’action. Dans le cas de l’Elbe, il a aussi été montré qu’une institution nationale étendue (la communauté du bassin de l’Elbe) peut fournir une plate-forme précieuse pour obtenir la coopération de tous les acteurs essentiels nationaux à l’intérieur d’un bassin fluvial.

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Affronter le défi mondial de la qualité des eaux est étroitement lié à de nombreuses autres priorités des sociétés, telle que la sécurité alimentaire et la santé. En conséquence, des mesures pour protéger la qualité des eaux devraient être intégrées à un concept plus large de durabilité et faire partie des efforts pour réaliser les nouveaux objectifs du développement durable. Les études de cas ont montré que le défi de la protection de la qualité des eaux est entremêlé à de nombreuses autres tâches des sociétés – fournir de l’alimentation, développer l’économie et fournir des installations sanitaires sûres. En conséquence, au cours des prochaines années, il sera très important de lier les objectifs pour la qualité des eaux avec d’autres objectifs du programme de développement durable de l’après 2015 et avec les nouveaux objectifs du développement durable.

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Резюме отчёта

Основные тезисы

• Для достижения целей устойчивого развития в области здравоохранения и обеспечения продовольственной и водной безопасности, необходимо наличие достаточного количества высококачественной воды. В связи с этим уровень загрязнения вод большинства рек Латинской Америки, Африки и Азии по сравнению с 90-ми годами прошлого века вызывает озабоченность. • Важно, чтобы меры, направленные на защиту и восстановление качества воды, осуществлялись совместно с мероприятиями для достижения Целей в области устойчивого развития и Повестки дня в области развития после 2015 г. • Серьёзное патогенное загрязнение водных ресурсов затрагивает уже около трети рек Латинской Америки, Африки и Азии. Кроме угрозы здоровью, связанной с потреблением питьевой загрязнённой воды, многие люди подвергаются риску заболеть через контакт с загрязнённой водой во время купания, стирки одежды и выполнения других бытовых дел. Число сельского населения на указанных выше континентах, подверженных такого рода рискам, может достигать сотен миллионов. • Серьёзные загрязнения органического характера уже наблюдаются примерно на одной седьмой части от общей протяжённости рек Латинской Америки, Африки и Азии, что вызывает озабоченность состоянием рыболовства в пресных водах и, соответственно, обеспечением продовольственной безопасности и средств к существованию. • Умеренный и высокий уровни минерализации воды наблюдаются примерно на одной десятой части от общей протяжённости рек Латинской Америки, Африки и Азии. Это тревожная тенденция, препятствующая использованию речной воды для орошения, в промышленности и для других целей. • Непосредственная причина увеличения загрязнения водоёмов заключается в росте объёма сбросов в реки и озёра сточных вод. Ключевые причины - рост численности населения, активная хозяйственная деятельность, интенсификация и расширение сельского хозяйства, а также увеличение объёмов неочищенных или прошедших низкий уровень обработки сточных вод. • От ухудшения качества воды в развивающихся странах больше всего страдают следующие уязвимые группы населения: женщины, часто использующие воду из открытых водоёмов для бытовых нужд; дети, для которых открытые водоёмы служат местом игр и которые нередко ходят за водой для нужд домашнего хозяйства; сельская беднота, для которой рыба является основным источником протеина; рыбаки с низким заработком, а также работники рыбных хозяйств, для которых промысел в пресноводных водоёмах является главным средством к существованию. • Хотя загрязнение воды и является серьёзной проблемой, и ситуация в Латинской Америке, Африке и Азии ухудшается, большая часть рек на этих трёх континентах пока находится в хорошем состоянии. Существует ряд возможностей для быстрого сокращения дальнейшего загрязнения и восстановления уже загрязнённых рек. Для выполнения этих задач требуется комплекс административных и технических мер при эффективной поддержке органов управления. • У развивающихся стран имеется большой выбор административных и технических возможностей борьбы с загрязнением воды. Десятилетия назад многие из этих мер были недоступны или

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не использовались в развитых странах, столкнувшихся с аналогичной ситуацией, связанной с ухудшением качества воды. • Мониторинг и оценка качества воды имеют важное значение для понимания глубины и масштабов глобальной проблемы качества воды. Однако, во многих странах мира ещё недостаточно хорошо налажен сбор данных для достижения этих задач. К примеру, плотность расположения станций мониторинга качества воды в Африке в сто раз меньше, чем во всём остальном мире. Поэтому актуальна задача расширения сбора, распространения и анализа данных о качестве воды в рамках международной программы мониторинга GEMS и других водных программ. «Горячие точки» с наиболее загрязнёнными водоёмами, показанные в данном отчёте, могут быть использованы для определения приоритетов в области сбора данных.

Люди и экосистемы одинаково нуждаются как в достаточном количестве воды, так и в соответствующем её качестве. Поэтому необходимо срочно определить места, где качество воды недостаточное или находится в зоне риска, и включить потребность в качественной воде в концепцию безопасного водообеспечения. В данном отчёте основное внимание уделяется качеству воды и её взаимосвязи с такими целями в области развития, как здоровье, продовольственная и водная безопасность. Для того, чтобы показать эту связь, здесь рассматриваются наиболее важные проблемы качества поверхностных вод, в том числе патогенное и органическое загрязнения, минерализация и эвтрофикация. Основное внимание уделено трём континентам - Латинской Америке, Африке и Азии. В течение последних нескольких лет повышение безопасности водообеспечения является важной международной задачей. В рамках достижения Целей в области развития и других мероприятий международное сообщество большое внимание уделяет количественной стороне этого вопроса путём расширения доступа населения к безопасному водообеспечению. Действительно, снабжение людей, промышленности и сельского хозяйства необходимым количеством воды является и должно оставаться важнейшей международной задачей. Однако возрастает значение другого аспекта водной безопасности – обеспечение соответствующего качества пресных вод. Это вызывает определенное беспокойство в связи с тем, что качество воды в реках и озёрах во всём мире переживает значительные изменения. Возрастающее внимание, уделяемое качеству воды, отражено в различных задачах Целей в области устойчивого развития. Качество воды значительно улучшилось во многих развитых странах, хотя ещё остаётся ряд проблем. В то же время в развивающихся странах по мере роста городского населения, уровня потребления и увеличения объёмов неочищенных сточных вод, нарастает тенденция загрязнения водоёмов. Однако, остаётся только гадать о реальной ситуации с качеством воды в пресных экосистемах в большинстве стран мира из-за отсутствия информационной базы. Поэтому в срочном порядке было необходимо проведение оценки для определения объёма и масштаба «состояния качества воды на глобальном уровне». Цель предварительного исследования - подготовка отдельных составных частей для полномасштабной оценки качества водных ресурсов мира, которые в дальнейшем можно будет расширить. Исследование также представляет собой предварительную оценку качества воды пресноводных экосистем мира с акцентом на реки и озёра трёх континентов. Проблема загрязнения большинства рек Латинской Америки, Африки и Азии усугубилась начиная с 90-х годов ХХ века.1 Оценка изменений, произошедших за период с 1990 по 2010 гг. была проведена по ключевым параметрам, отражающим патогенное загрязнение (присутствие бактерий кишечной палочки фекального происхождения), органическое загрязнение (биохимическая потребность в кислороде; БПК) и минерализацию (общее количество растворённых твёрдых веществ; TDS). Показатели патогенного и органического загрязнения ухудшились более чем на половине общей протяженности рек всех трёх

1В данном отчёте под континентами Латинская Америка, Африка и Азия следует понимать следующие субрегионы в соответствии с отчётом ЮНЕП «Глобальная экологическая перспектива»: Латинская Америка = Центральная Америка, Южная Америка, Карибский бассейн; Африка = Центральная Африка, Восточная Африка, Северная Африка, Южная Африка, Западная Африка, западная часть Индийского океана; XLIV Азия = Центральная Азия, Северо-Восточная Азия, Юго-Восточная Азия, Западная Азия (Аравийский полуостров и Машрик).

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континентов, в то время как показатели минерализации ухудшились почти на треть.2 Это является особым поводом для беспокойства в отношении некоторых участков рек, где загрязнение воды достигло серьёзного уровня, или там, где этот уровень наблюдался уже в 1990 г., а ухудшение показателей фиксировалось к 2010 г. Серьёзные патогенные загрязнения3 уже затрагивают примерно одну треть всех рек в Латинской Америке, Африке и Азии. Доля сельского населения на этих континентах, чьё здоровье подвергается опасности через контакт с загрязнёнными водами открытых водоёмов, может достигать нескольких сотен миллионов человек. К наиболее уязвимым группам населения относятся женщины и дети. Согласно оценкам, серьёзное патогенное загрязнение (при котором ежемесячные показатели концентрации бактерий кишечной палочки в водном потоке достигают более 1000 КОЕ/100мл4) затрагивает около четверти рек Латинской Америки, 10–25 процентов рек Африки и от одной трети до половины рек в Азии. Соответственно, наибольшая степень патогенного загрязнения среди трёх континентов наблюдается в Азии. По оценкам, доля сельского населения, контактирующего с водами в открытых водоёмах,5 и находящихся под угрозой, примерно составляет 8–25 млн в Латинской Америке, 32–164 млн в Африке и 31–134 млн человек в Азии. Широкий диапазон этих оценок показывает, что многое о реальной опасности ещё не известно, но в то же время указывает и на то, что число людей в зоне риска, скорее всего, очень велико. Данные оценки не включают ни фермеров, подвергающихся воздействию загрязнённых вод, используемых для орошения, ни жителей городов. В частности, риску подвергаются женщины, часто использующие воду из открытых водоёмов для стирки одежды, питья и приготовления пищи, а также дети, для которых открытые водоёмы служат местом игр и которые нередко ходят за водой для домашних нужд. Стоит отметить, что с 1990 по 2010 гг. показатели концентрации кишечной палочки выросли почти в двух третях всех рек Латинской Америки, Африки и Азии. Общая протяжённость участков рек, вызывающих «растущую озабоченность»6, достигает четверти от всей протяжённости рек на этих континентах. Здесь уровень содержания бактерий кишечной палочки достиг серьёзного или уже находился на серьёзном уровне в 1990 г. и только усугубился к 2010 г. Такие зоны можно считать «горячими точками». Рост показателей связан с расширением канализационных систем, сбрасывающих неочищенные сточные воды в открытые водоёмы. С одной стороны, канализация, отводя сточные воды от населённых пунктов, позволила снизить риск для здоровья, связанный с небезопасными санитарно-гигиеническими условиями на поверхности земли. С другой стороны, сброс неочищенных сточных вод в открытые водоёмы перенёс опасность для здоровья человека с суши на воду. Результаты исследований показывают, что, если бы не строительство канализации, содержание бактерий кишечной палочки фекального происхождения в африканских реках могло бы быть ниже на 23 процента. Тем не менее, решение заключается не в сокращении строительства канализационных коллекторов, а в очистке поступающих туда сточных вод. Уже сегодня серьёзные органические загрязнения охватывают каждый седьмой километр рек в Латинской Америке, Африке и Азии. Высокий уровень органического загрязнения и тенденция его роста вызывает озабоченность состоянием рыболовства в пресноводных водоёмах и, следовательно, обеспечением продовольственной безопасности и средств к существованию. В группу риска входят сельская беднота, для которой пресноводная рыба является основным источником протеина, рыбаки с низким уровнем дохода, а также работники рыбных хозяйств, для которых промысел в пресноводных водоёмах является основным средством к существованию. Причина органического загрязнения в попадании в открытые водоёмы значительных объёмов разлагаемых органических соединений, разложение которых в воде часто приводит к серьёзному снижению содержания растворённого кислорода, необходимого рыбам и прочей водной фауне.

2В данном отчёте для отражения результатов анализов использованы округленные данные. С учётом неточностей в оценках, лежащих в основе отчёта, было целесообразным представить округленные показатели. Основной текст отчёта представляет данные исследований, лежащие в основе отчёта. 3Определение серьёзного уровня патогенного загрязнения представлено в примечании 5. Водоёмы, подвергшиеся такому загрязнению, с высокой долей вероятности, отличаются уровнем содержания патогенов, индикатором которого является высокий уровень концентрации бактерий кишечной палочки фекального происхождения. Это подразумевает, что здоровье людей, находящихся в контакте с такими водами, под угрозой. 4Стандартной единицей измерения уровня концентрации кишечной палочки фекального происхождения является количество «колониеобразующих единиц» (КОЕ) на 100 мл образца воды. 4Включает людей, контактирующих с речной водой, в которой патогенное загрязнение достигает серьёзного уровня (x > 1000 КОЕ/100 мл). 4Понятие «растущая озабоченность» в данном отчёте означает достижение категории серьёзного уровня загрязнения 2008–10 гг. или нахождение на уровне серьёзного загрязнения 1990-92 гг., а также дальнейшее ухудшение в 2008–10 гг. XLV

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Благодаря промыслу рыбы во внутренних водах обеспечивается значительная часть белка в рационе жителей развивающихся стран. На общемировом уровне внутриконтинентальное рыболовство является шестым по значимости поставщиком животного белка, при этом в некоторых развивающихся странах промысел рыбы в материковых водоёмах поставляет более 50 процентов животных белков, производимых в данных странах. В развивающихся странах рыболовный промысел во внутренних водах также является важным источником получения дохода. Промысел обеспечивает работой 21 млн рыбаков и создаёт 38,5 млн смежных рабочих мест. Почти все рабочие места сосредоточены в мелких рыболовных хозяйствах, где в основном занята беднота, более половины которой составляют женщины. Поэтому не может не беспокоить тот факт, что, как минимум 10 процентов оценок, проведённых в Латинской Америке, Африке и Азии, дают тревожные показатели по, как минимум, трём из пяти параметров качества воды, имеющих особое значение для здорового развития рыболовного промысла. По оценкам 2010 г., серьёзное органическое загрязнение (с ежемесячной концентрацией БПК в воде более 8 мг/л) охватывало до одной десятой доли всей протяжённости рек в Латинской Америке, до одной седьмой в Африке и до одной шестой в Азии. Обеспокоенность вызывает и то, что уровень органического загрязнения (индикатором которого является рост концентрации БПК) с 1990 по 2010 гг. вырос почти в двух третях всех рек в Латинской Америке, Африке и Азии. Доля участков рек, вызывающих «растущую озабоченность», составляет около одной десятой от всей протяжённости рек на этих континентах, где показатели БПК достигли серьёзного уровня или находились на этом уровне загрязнения в 1990 г. и ещё более усугубились к 2010 г. Такие участки можно считать «горячими точками». Сильный и средний уровни минерализации водных ресурсов уже затрагивает около одной десятой рек Латинской Америки, Африки и Азии, что вызывает беспокойство, так как высокий уровень минерализации негативно влияет на использование речной воды для орошения, в промышленности и для других целей. В группу риска, затронутую проблемой минерализации воды, входят малообеспеченные фермеры, вынужденные использовать поверхностные воды для орошения своих земельных участков. Минерализация происходит тогда, когда концентрация растворённых солей и других веществ в реках и озёрах достигает высокого уровня, ограничивающего пригодность воды для использования. Несмотря на то, что воды почти всех рек содержат определенный уровень солей вследствие вымывания почвы и скальных пород в речной бассейн, человечество значительно увеличило этот уровень, сливая в реки высокоминерализованные стоки оросительных систем, бытовые сточные воды и стоки из шахт. На исследованных континентах минерализация воды распространена меньше, чем патогенное или органическое загрязнения. Тем не менее, умеренный и высокий уровень минерального загрязнения, если рассматривать их вместе (к примеру, там, где ежемесячная концентрация в потоке растворённых твёрдых частиц превышает 450 мг/л), затрагивают каждый двадцатый километр всех рек в Латинской Америке, до одной десятой всей протяжённости рек в Африке и до одной седьмой общей протяжённости рек в Азии. Речная вода, относящаяся к категории умеренного загрязнения, частично ограничена для использования в орошении, и не может быть использована для определённых промышленных целей без дополнительной очистки. Наиболее уязвимой группой населения, по всей вероятности, являются бедные фермеры, зависящие от поверхностных вод как источника поливной воды для своих небольших наделов. С 1990 по 2010 гг. минерализация вод увеличилась почти на одной трети от общей протяжённости рек на всех трёх континентах. Отдельные участки этих рек (несколько процентов от общей протяжённости) вызывают «растущую озабоченность», так как содержание в воде растворённых твёрдых частиц возросло до серьёзного уровня или находилось на серьёзном уровне в 1990 г. и ещё более ухудшилось к 2010 г. Антропогенные нагрузки питательных веществ на крупные озёра имеют большое значение и могут стать причиной дальнейшей эвтрофикации этих водоёмов. Тенденции роста таких нагрузок отличаются в каждом регионе мира. Эвтрофикацией называется пресыщение вод озёр и других водоёмов удобрениями, что приводит к

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нарушению естественных процессов. Эвтрофикация, как правило, вызывается антропогенным смывом в озёра фосфора, однако, свою роль играет и повышение уровня содержания азота. Более половины фосфора, попадающего в 23 из 27 крупнейших озёр7 по всему миру, приходит туда из антропогенных источников. Таким образом, большая часть крупных озёр Латинской Америки и Африки страдают от растущего уровня содержания фосфора. Для сравнения, в Северной Америке и Европе эти показатели падают благодаря эффективным мерам по снижению уровня фосфора. Непосредственной причиной растущего уровня загрязнения водных ресурсов является рост объёмов сброса сточных вод в реки и озёра, при этом основные источники загрязнения отличаются разнообразием загрязняющих веществ. Конечные причины увеличения уровня загрязнения - рост населения, экономическая активность, интенсификация и расширение сельского хозяйства при отсутствии или низкой степени очистки сточных вод. Сбор сточных вод в канализации снижает прямой контакт населения с отходами и патогенными веществами и, соответственно, является важной стратегией здравоохранения. Однако строительство канализаций привело к повышению концентрации загрязняющих веществ при сбросе стоков в поверхностные воды, что сместило зону риска для здоровья населения. Крупнейшим источником патогенного загрязнения (содержание бактерий кишечной палочки фекального происхождения) в Латинской Америке является бытовая сточная вода в коллекторах, в Африке – домашние отходы, не попадающие в канализацию, а в Азии на первом месте находятся бытовые сточные воды из канализации, за которыми с небольшим отрывом следуют бытовые отходы, не попадающие в канализацию. Самым большим источником органического загрязнения (БПК) в Латинской Америке являются бытовые сточные воды из канализации, в Африке – бытовые отходы, не попадающие в канализацию, а в Азии – сточные промышленные отходы. Крупнейшим антропогенным источником повышения уровня минерализации (общее содержание в воде растворённых твёрдых частиц) в Латинской Америке является промышленность, а в Африке и Азии – орошаемое земледелие. Основным антропогенным источником повышения содержания фосфора в крупнейших озёрах Латинской Америки являются отходы животноводства и неорганических удобрений, в Африке – отходы животноводства, в Азии и Европе – бытовые сточные воды, отходы животноводства и также как и в Северной Америке – неорганических удобрений. отя загрязнение водных источников и является серьёзной проблемой, и ситуация в Латинской Америке, Африке и Азии ухудшается, большая часть рек на этих трёх континентах пока находится в хорошем состоянии, что даёт широкие возможности для сокращения дальнейшего загрязнения и восстановления уже загрязнённых рек. В предыдущих пунктах основной упор был сделан на обширные участки рек с плохим качеством воды и тенденцией к дальнейшему её ухудшению. Однако есть и другая сторона медали. Многие участки рек пока ещё не подверглись загрязнению: • В примерно половине до двух третей общей протяженности рек (в Латинской Америке, Африке и Азии) наблюдается низкий уровень патогенного загрязнения; • В более чем трёх четвертях всех рек низкий уровень органического загрязнения; • Примерно в девяти десятых наблюдается низкий уровень минерализации. Пока ещё есть возможность предотвратить серьёзное загрязнение этих чистых участков рек и, кроме того, начать восстановление уже загрязнённых. Существует значительное количество мер, которые можно принять с целью избежания растущего загрязнения и восстановления загрязнённых пресных вод: 1. Мониторинг. Необходимо более глубокое понимание интенсивности и масштаба глобальной проблемы качества воды. Для этого необходимо срочно расширить мониторинг качества воды как в развивающихся странах, так и на международном уровне через системы мониторинга воды как GEMS. 2. Оценка. Необходимы всеобъемлющие оценки качества воды в мире на национальных и

7В данном отчёте под понятием «крупнейшие мировые озёра» имеются в виду пять крупнейших по площади поверхности озёр в каждом из пяти регионов по версии «Глобальной экологической перспективы» ЮНЕП (Африка, Азия, Европа, Латинская Америка и Северная Америка). XLVII

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международном уровнях. Такого рода оценки необходимы для определения приоритетов и действий, направленных на борьбу с проблемой загрязнения воды. 3. Старые и новые административные и технические меры. Развивающиеся страны имеют возможность не просто применять традиционные меры обработки сточных вод, но и воспользоваться гораздо большим количеством административных и технических мер для управления качеством воды, включая решения, основанные на природных процессах. 4. Создание эффективных институтов. Немаловажным элементом в управлении качеством воды является создание институтов, содействующих активной деятельности и преодолению барьеров для борьбы с загрязнением воды. Данные идеи более детально освещены в представленных ниже пунктах. I. Мониторинг Получение всесторонней глобальной оценки качества воды не представляется возможным из-за недостатка данных о качестве поверхностных вод в единственной всемирной базе данных о состоянии качества воды GEMStat. GEMStat обладает крайне низкой плотностью расположения измерительных станций в сравнении с принятой минимальной плотностью от 1,5 до 4 станций на 10 000 км2 площади речного бассейна как, к примеру, в США и Европе. Также в GEMStat содержатся данные только о 71 из 110 имеющихся речных бассейнов, а плотность станций составляет 0,5 на 10 000 км² или даже меньше. С 1990 по 2010 гг. средняя плотность станций в Латинской Америке составляет 0,3 на 10 000 км², в Африке – 0,028 на 10 000 км², а в Азии – 0,08 на 10 000 км². Наиважнейшей задачей является расширение временного и пространственного охвата данных мониторинговыми станциями вместо увеличения количества параметров, собираемых на существующих станциях. Учитывая высокую стоимость мониторинга, необходимо правильно расставить акценты и решить, на каких реках, данных по которым недостаточно, нужно провести замеры в первую очередь. «Горячие точки», определенные в данном отчёте, могут быть использованы в качестве предварительных данных при принятии решения о том, в каком направлении расширить мониторинг. Причины недостаточного охвата данных заключатся в политических, институциональных и технических проблемах. Однако существует множество альтернатив для улучшения охвата данных о качестве воды. Одно из альтернативных решений для улучшения охвата данных - использование дистанционного зондирования. Актуальные записи охватывают ключевые переменные показатели качества воды в озёрах, а в ближайшее время будут доступны и данные по рекам. Преимуществом дистанционного зондирования является широкая зона охвата и сбора данных как по временным, так и по пространственным характеристикам. К недостаткам относится ограниченное число переменных показателей, по которым можно провести замеры, и обработка требуемых исходных данных. Другие варианты улучшения охвата данных о качестве воды: (I) активные усилия по включению данных, полученных на национальном и региональном уровнях, в существующие базы данных; (II) создание национальных рабочих групп для мониторинга состояния пресных вод, в задачи которых будет входить дальнейший обмен данными о качестве водных источников со своими коллегами из других стран, (III) получение данных с помощью научных проектов отдельных лиц. Дополнительное преимущество «гражданской науки» заключается в вовлечении широкой общественности в деятельность по очистке загрязнённых вод. Собранные данные должны широко распространяться и быть доступными на таких цифровых площадках, как UNEP Live. Также данные должны быть легкодоступными в связи с мониторингом и осуществлением Целей в области устойчивого развития. II. Оценка Для оценки состояния уровня знаний обо всех ключевых аспектах качества воды необходимо проведение глобальной полномасштабной оценки качества воды, что позволит осветить связи между качеством воды

8Без учета засушливых районов в континентальной области.

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и другими вопросами, связанными с Целями в области развития после 2015 г., как здравоохранение и обеспечение продовольственной безопасности, а также для определения приоритетных направлений исследований и действий. Оценка должна быть: • Многоуровневой и охватывать глобальные данные вместе с национальными и тематическими оценками; • Прозрачной и обеспечивающей участие широкого круга заинтересованных сторон и учёных. Оценка должна включать: • Цели и темы, совместно отобранные политиками и научными сообществами; • Анализ вариантов политических решений для защиты и восстановления качества воды; • Широкий доступ к результатам на современных цифровых платформах (к примеру, на UNEP Live). Оценку также следует использовать как возможность для повышения технического потенциала развивающихся стран и обеспечения их доступа к результатам последних научных исследований. III. Административные и технические меры У развивающихся стран имеется множество доступных возможностей, позволяющих предотвратить ухудшение качества воды в своих реках и озёрах. Десятилетия назад многие из них были недоступны или не использовались в развитых странах, столкнувшихся с аналогичной ситуацией, связанной с ухудшением качества воды. Основные технические параметры: (i) Профилактика загрязнения, которая позволяет бороться с причиной загрязнения, прежде чем она перерастёт в проблему; (ii) Очистка и обработка загрязнённой воды, являющиеся традиционным подходом к сокращению концентрации загрязняющих веществ перед тем, как они попадают в поверхностные воды; (iii) Безопасное повторное использование сточных вод для орошения и других целей; (iv) «Природные решения», включающие восстановление и защиту экосистем, к примеру, восстановление лесных массивов в речных бассейнах для сокращения эрозии и выброса осадочных отложений в реки или восстановление водно-болотных угодий для удаления загрязняющих веществ из городских или сельскохозяйственных стоков. За этими подзаголовками скрывается множество новых идей, которые не были доступны для развитых стран, впервые столкнувшихся с аналогичным ухудшением качества воды около трёх десятилетий назад. В число новых идей входят экологически чистое промышленное производство, биоинженерные очистные сооружения, нулевой сброс неочищенных сточных вод и платежи за экосистемные услуги в лесистых верховьях рек. Чтобы контролировать различные типы и источники загрязнения воды потребуются различные технические решения. Стоит попытаться сгруппировать и объединить эти решения в пакеты, которые можно будет применить ко многим речным бассейнам. С одной стороны, как это было отмечено выше, основные источники загрязнения различаются по типам загрязнения воды. Это означает, что универсальное решение по принципу «одно на всех» не сработает для решения глобальной проблемы качества воды. С другой стороны, схожие проблемы, связанные с качеством воды, появляются по всему миру, несмотря на то, что места и ситуации сильно различаются. Поэтому представляется возможным разработать различные варианты пакетов технических решений, которые можно будет применять ко множеству различных речных бассейнов со схожими проблемами. IV. Государственное управление и институты Опыт работы в различных речных бассейнах показывает важность надлежащего государственного управления и эффективности институтов управления качеством воды.

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Были установлены следующие значительные препятствия на пути решения проблемы загрязнения воды: • Раздробленность властных структур в пределах одного речного бассейна; • Отсутствие технического потенциала; • Отсутствие у общественности знаний о причинах загрязнения воды. Опыт проведённой работы показывает, что для преодоления этих и других препятствий в качестве первого шага эффективно проведение образовательной кампании, которая поможет заручиться поддержкой общественности для борьбы с загрязнением водных ресурсов. Другим уроком стал тот факт, что ключевым шагом на пути восстановления рек и озёр является согласованный со всеми главными действующими лицами в бассейне реки план действий. Ещё одним ключевым институциональным шагом для защиты вод рек, протекающих по территориям нескольких стран, является создание таких совместных органов для разработки и осуществление плана действий, как международные комиссии по рекам Эльба и Вольта. На примере Эльбы видно, что широкий охват различного рода государственных учреждений (сообщество бассейна реки Эльбы) может стать ценной площадкой для сотрудничества всех важнейших национальных субъектов в пределах речного бассейна. Борьба с глобальной проблемой качества воды тесно связана с рядом таких приоритетных задач общества, как продовольственная безопасность и здоровье. Поэтому действия, направленные на защиту качества воды, должны быть включены в более широкую концепцию устойчивого развития и стать частью мероприятий, осуществляемых для достижения новых Целей устойчивого развития. Опыт работы показал, что проблема защиты качества воды переплетается с рядом других задач общества, как то обеспечение продовольствием, развитие экономики и предоставление безопасных санитарных условий. Поэтому в ближайшие годы важно увязать цели в защиту качества воды с другими целями Повестки на период после 2015 года и новыми Целями в области устойчивого развития.

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Resumen Ejecutivo

Puntos principales

• Para cumplir con los Objetivos de Desarrollo Sostenible, entre ellos los objetivos de salud, seguridad alimentaria y seguridad del agua, son necesarias tanto una buena calidad del agua como una cantidad adecuada de la misma. Por lo tanto, constituye una gran preocupación el hecho de que la contaminación del agua haya empeorado desde la década de 1990 en la mayoría de los ríos de América Latina, África y Asia. • Es importante que las acciones realizadas para proteger y mejorar la calidad del agua estén relacionadas con las iniciativas que se realicen para cumplir con los Objetivos de Desarrollo Sostenible y la Agenda de Desarrollo Post 2015. • La contaminación patógena severa ya afecta a cerca de un tercio de todos los tramos de río de América Latina, África y Asia. Además del riesgo a la salud que implica beber agua contaminada, muchas personas también corren el riesgo de contraer enfermedades por contacto con aguas superficiales contaminadas para el baño, el lavado de ropa y otras actividades domésticas. El número de habitantes de zonas rurales que corren estos riesgos puede ascender a cientos de millones en estos continentes. • La contaminación orgánica severa ya afecta a cerca de un séptimo de todos los tramos de río de América Latina, África y Asia, y constituye una gran preocupación para el estado de la pesca de agua dulce y, por lo tanto, para la seguridad alimenticia y la subsistencia. • La contaminación salina severa y moderada afecta a cerca de un décimo de todos los tramos de río de América Latina, África y Asia, y constituye una preocupación porque afecta el uso del agua de río para el regadío, la industria y otros propósitos. • La causa inmediata del aumento de la contaminación del agua es el crecimiento de las cargas de aguas residuales en ríos y lagos. Las causas principales son el crecimiento de la población, el aumento de la actividad económica, la intensificación y expansión de la agricultura, y una mayor cantidad de enganches de alcantarillado con un nivel bajo o nulo de tratamiento. • Entre los grupos más vulnerables al deterioro de la calidad del agua en los países en vías de desarrollo se encuentran las mujeres, debido a que utilizan frecuentemente aguas superficiales para actividades domésticas; los niños, porque llevan a cabo actividades recreativas en aguas superficiales locales y porque frecuentemente se les asigna la tarea de recolectar agua para el hogar; los habitantes de zonas rurales de bajos recursos que consumen pescado como fuente importante de proteína; y los pescadores y trabajadores de la pesca de bajos recursos que dependen de la pesca de agua dulce para subsistir. • Aunque la contaminación del agua es grave y actualmente empeora en América Latina, África y Asia, la mayoría de los ríos en estos tres continentes aún se encuentra en buenas condiciones, y existen excelentes oportunidades para detener la contaminación y restablecer la calidad de los ríos contaminados. Para esta labor, se necesitará una mezcla de opciones técnicas y de gestión respaldada por una buena gobernanza. • Una amplia gama de opciones técnicas y de gestión se encuentra al alcance de los países en vías de desarrollo para el control de la contaminación del agua. Muchas de estas opciones no se encontraban disponibles o no fueron utilizadas por los países desarrollados cuando estos se vieron enfrentados a una calidad del agua en similar deterioro hace algunas décadas.

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• La monitorización y la evaluación de la calidad del agua son esenciales para entender la intensidad y el alcance del desafío mundial de la calidad del agua, aunque la cobertura de recolección de datos en muchas partes del mundo es inadecuada para este objetivo. Por ejemplo, la densidad de estaciones de medición de calidad del agua en África es cien veces menor que la densidad usada en otras partes del mundo para efectos de monitorización. Así, se debe expandir urgentemente la recopilación, distribución y análisis de datos de calidad del agua a través del programa internacional SIMUVIMA/ Agua y otras actividades. Los puntos críticos de contaminación del agua identificados en este informe pueden ser utilizados para establecer prioridades para la recolección de datos.

Las personas y los ecosistemas requieren una cantidad adecuada de agua, así como una calidad adecuada de la misma. Por lo tanto, resulta urgente evaluar en qué lugares la calidad del agua es inadecuada o se encuentra en riesgo e incorporar la necesidad de agua de buena calidad al concepto de seguridad del agua. El presente informe se enfocará en la calidad del agua y su relación con objetivos de desarrollo tales como salud, seguridad alimentaria y seguridad del agua. Para establecer esta conexión, el informe revisará los principales problemas de calidad del agua en aguas superficiales, entre ellos la contaminación patógena, la contaminación orgánica, la contaminación salina y la eutrofización. Nos concentraremos en tres continentes: América Latina, África y Asia.

El fortalecimiento de la seguridad del agua ha sido una prioridad internacional durante los últimos años. A través de los Objetivos de Desarrollo del Milenio y otras iniciativas, la comunidad internacional ha priorizado el aspecto cantidad de la seguridad del agua incrementando el acceso de las personas a un abastecimiento seguro de agua. Sin duda que abastecer una cantidad apropiada de agua a las personas, a la industria y a la agricultura es, y debe seguir siendo, una importante prioridad internacional. Sin embargo, otra dimensión de la seguridad del agua se vuelve cada vez más importante: asegurar que el agua dulce posea una calidad adecuada. Lo anterior constituye una preocupación pues la calidad del agua de los ríos y lagos del mundo está sufriendo cambios importantes. La prioridad cada vez más grande que se le da a la calidad del agua se refleja en varias de las metas de los Objetivos de Desarrollo Sostenible. La calidad del agua ha mejorado notablemente en muchos países desarrollados, aunque algunos problemas persisten. Mientras tanto, en los países en vías de desarrollo la tendencia es al aumento de la contaminación del agua a medida que la población urbana crece, el consumo material aumenta y los volúmenes de aguas residuales no tratadas se expanden. No obstante, la situación real de la calidad del agua en los ecosistemas de agua dulce en muchas partes del mundo es solo objeto de especulación debido a la falta de información básica. De esta forma, se necesita urgentemente una evaluación que identifique el alcance y la escala del “desafío mundial de la calidad del agua”. El presente Pre-Estudio tiene como objetivo proporcionar algunas de las piezas esenciales para una evaluación mundial a gran escala de la calidad del agua que puedan ser transformadas en una evaluación completa. El informe también presenta una estimación preliminar de la situación de la calidad del agua en los ecosistemas de agua dulce del mundo, con énfasis en los ríos y lagos de tres continentes. La contaminación del agua ha empeorado desde la década de 1990 en la mayoría de los ríos de América latina, África y Asia.1

Se han estimado los cambios entre 1990 y 2010 en los parámetros clave de los ríos que reflejan la contaminación patógena (bacteria coliforme fecal), la contaminación orgánica (demanda bioquímica de oxígeno; DBO), y la contaminación salina (total de sólidos disueltos; TDS, por sus siglas en inglés). El nivel de contaminación patógena y orgánica empeoró en más de 50 por ciento de los tramos de río en los tres continentes, mientras que la contaminación salina empeoró en casi un tercio2. Este empeoramiento genera especial preocupación en un subgrupo de estos tramos de río en los que la contaminación del agua ha alcanzado un nivel severo, o ya se encontraba en un nivel severo en 1990 y en 2010 se ha encontrado peor.

1En el presente informe se usan las siguientes subregiones de las “Perspectivas del Medio Ambiente Mundial” del PNUMA para definir “América Latina”, “África” y “Asia”: América Latina = América Centrral, América del Sur y el Caribe; África = África Central, África Oriental, África Septentrional, África Meridional, África Occidental, Océano Índico Occidental; Asia= Asia Central, Asia Nororiental, Asia Meridional, Asia Suroriental, región de Asia Occidental (Península Arábiga, Mashriq). 2En este resumen, se usan cifras redondeadas para los resultados de análisis. Es adecuado presentar resultados redondeados considerando las incertidumbres de LII las estimaciones subyacentes. El texto principal presenta estas estimaciones subyacentes.

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La contaminación patógena severa3 ya afecta a cerca de un tercio de todos los tramos de río de América Latina, África y Asia. El número de habitantes de zonas rurales cuya salud corre peligro por el contacto con aguas superficiales contaminadas puede llegar a los cientos de millones en estos continentes. Entre los grupos más vulnerables se encuentran mujeres y niños.

Se estima que la contaminación patógena severa (en la que las concentraciones mensuales en caudal de bacteria coliforme fecal son de > 1000 cfu/100ml4) afecta a cerca de un cuarto de los tramos de río de América Latina, a cerca de 10 a 25 por ciento de los tramos de río de África y a cerca de entre un tercio y la mitad de los tramos de río de Asia. Así, de los tres continentes, el alcance de la contaminación patógena parece ser mayor en Asia. Considerando la fracción de población rural que tiene probabilidades de entrar en contacto con aguas superficiales5, se estima que aproximadamente entre 8 y 25 millones de personas se encuentran enriesgo en América Latina, entre 32 y 164 millones en África, y entre 31 y 134 millones en Asia. El amplio rango de estas estimaciones muestra que aún existen muchas dudas sobre el riesgo real, pero también que las cifras de personas en riesgo probablemente son muy altas. Estas estimaciones no incluyen a agricultores expuestos a aguas contaminadas de regadío ni a la población urbana. La mujeres corren un riesgo particular debido a que utilizan frecuentemente aguas de ríos y lagos para lavar ropa, cocinar y beber en el hogar. Niños y niñas también corren un riesgo acentuado pues llevan a cabo actividades recreativas en aguas superficiales locales y también normalmente se les asigna la tarea de recolectar agua para el hogar. Cabe destacar que la concentración de bacteria coliforme fecal ha aumentado entre 1990 y 2010 en casi dos tercios de todos los ríos de América Latina, África y Asia. Los tramos de río con una “tendencia al alza de especial preocupación”6 conforman cerca de un cuarto de los kilómetros totales de los ríos en estos continentes donde los niveles de bacteria coliforme fecal habían alcanzado un nivel severo en 1990 y se encontraban en un nivel peor en 2010. A esta áreas se las puede considerar puntos críticos. Una gran parte del aumento se debe a la expansión de los sistemas de alcantarillado que descargan aguas residuales no tratadas en aguas superficiales. Por un lado, retirando las aguas residuales de las zonas pobladas, las alcantarillas han reducido el riesgo a la salud que constituyen las prácticas inseguras de saneamiento en tierra. Por otro lado, descargando aguas residuales no tratadas en aguas superficiales, han transferido el riesgo a la salud desde la tierra hacia las aguas superficiales. Se estimó que si no se hubiesen construido alcantarillas, las cargas de coliforme fecal en los ríos de África en 2010 podrían haber sido 23 por ciento menor. La solución, sin embargo, no es construir menos alcantarillas, sino tratar las aguas residuales que estas recogen. La contaminación orgánica severa ya afecta a cerca de uno de cada siete kilómetros de todos los tramos de río de América Latina, África y Asia. El alto nivel de contaminación orgánica y su tendencia al alza son una preocupación que afecta a la industria de la pesca de agua dulce y, por lo tanto, la seguridad alimentaria y la subsistencia. Los grupos afectados por la contaminación orgánica incluyen los habitantes de zonas rurales de bajos recursos que dependen del pescado de agua dulce como fuente principal de proteína en la dieta, y pescadores y trabajadores de la pesca de bajos recursos que dependen de la pesca de agua dulce para subsistir.

La contaminación orgánica es causada por el depósito de grandes cantidades de compuestos orgánicos degradables en los cuerpos de aguas superficiales. La descomposición de estos compuestos normalmente conlleva una grave reducción de los recursos de oxígeno disuelto de un río de los que dependen peces y otra fauna acuática. Los peces de aguas interiores constituyen una parte importante de las proteínas de la dieta de las personas de países en vías de desarrollo. Mundialmente, la pesca de agua dulce es la sexta fuente más importante de proteína animal, pero en algunos países en vías de desarrollo la pesca en aguas interiores es responsable por más de 50 por ciento de la proteína animal producida por país. La pesca de agua dulce también es una importante fuente de subsistencia en los países en vías de desarrollo. La pesca de agua dulce en estos países da empleo a 21 millones de pescadores y genera 38,5 millones de empleos relacionados, casi todos ellos en pequeñas empresas pesqueras y ocupados mayoritariamente por personas de bajos recursos, de las cuales más de la mitad son mujeres. Por este motivo es alarmante que al menos 10% de

3El nivel severo de contaminación patógena se define en la Nota al Pie 5. Tales cuerpos de agua tienen la probabilidad de presentar niveles de patógenos como indica un alto nivel de bacteria coliforme fecal, lo que implica que las personas que entran en contacto con estas aguas están expuestas a un alto riesgo a la salud. 4La unidad de medida estándar de concentración de coliforme fecal son las “unidades formadoras de colonias” (cfu, por sus siglas en inglés) por cada 100 ml de muestra de agua. 5Esto incluye a las personas que entran en contacto con ríos que tienen un nivel severo de contaminación patógena (x > 1000 cfu / 100 ml) 6“Tendencia al alza de especial preocupación” en este informe significa un nivel de contaminación que aumentó a categoría de contaminación severa en 2008- LIII 2010 o que ya se encontraba en dicha categoría en 1990–1992 y continuó aumentando su concentración en 2008–2010.

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todas las mediciones de América Latina, África y Asia muestren niveles preocupantes para al menos tres de cinco parámetros de calidad del agua de especial relevancia para la salud de las empresas de pesca. En 2010, se estimó que la contaminación orgánica severa (en la que las concentraciones mensuales en caudal de DBO son > 8 mg/l) afectó hasta cerca de un décimo de los tramos de río de América Latina, hasta cerca de un séptimo de los tramos de río de África, y hasta cerca de un sexto de los tramos de río de Asia. También genera gran preocupación que la contaminación orgánica (como demuestran las crecientes concentraciones en río de DBO) haya aumentado entre 1990 y 2010 en casi dos tercios de todos los ríos de América Latina, África y Asia. Un subgrupo de estos tramos de río con una “tendencia al alza deespecial preocupación” conforma cerca de un décimo del total de kilómetros de los ríos de estos continentes en los que los niveles de DBO aumentaron a un nivel severo, o en los que ya se encontraban en un nivel severo en 1990 y se han encontrado peor en 2010. Estos ríos pueden ser considerados puntos críticos. La contaminación salina severa y moderada ya afecta a cerca de un décimo de todos los tramos de río de América Latina, África y Asia y genera preocupación porque los altos niveles de salinidad afectan el uso de aguas de río para el regadío, la industria y otros propósitos. Los grupos afectados por la contaminación salina incluyen los agricultores de bajos recursos que dependen de aguas superficiales para el regadío de sus pequeños terrenos.

La “contaminación salina” ocurre cuando la concentración de sales disueltas y otras sustancias en ríos y lagos es lo suficientemente alta para interferir en el uso de estas aguas. Aunque casi todos los ríos tienen cierto contenido de sales debido al desgaste de los suelos de su cuenca hidrográfica, la sociedad se ha encargado de aumentar estos niveles descargando en los ríos caudales de retorno de agua de regadío, aguas residuales domésticas y vertidos de la minería. La contaminación salina es menos común que las contaminaciones patógena y orgánica en los continentes estudiados. No obstante, la contaminación salina moderada y severa juntas (en las que las concentraciones mensuales en caudal de TDS son > 450 mg/l) afectan a uno de cada veinte kilómetros de río en América Latina, hasta cerca de un décimo de los tramos de río en África, y hasta cerca de un séptimo de los tramos de río en Asia. El agua de río dentro de la categoría de contaminación moderada se reserva parcialmente para el uso en regadío, y no se le puede dar ciertas aplicaciones industriales sin una purificación adicional. Los agricultores de bajos recursos que dependen de aguas superficiales como fuente de agua de regadío para sus pequeños terrenos podrían verse particularmente afectados. La contaminación salina ha aumentado entre 1990 y 2010 en casi un tercio de todos los ríos de los tres continentes. Un subgrupo de estos tramos de río (un pequeño porcentaje de todos los tramos de río) presenta una “tendencia al alza de especial preocupación” en la que los niveles de TDS alcanzaron un nivel severo en 1990, o se ya encontraban en un nivel severo en 1990 y se han encontrado peor en 2010. Las cargas antropogénicas de nutrientes en lagos importantes son significativas y podrían causar o empeorar la eutrofización en estos lagos. Las tendencias de estas cargas son diferentes en diversas partes del mundo.

La eutrofización es la fertilización excesiva de lagos y otros cuerpos de agua que conlleva una alteración de sus procesos naturales. La eutrofización de los lagos normalmente es causada por cargas antropogénicas de fósforo, aunque las cargas de nitrógeno también se encuentran implicadas. Más de la mitad de las cargas totales de fósforo en 23 de 25 lagos importantes7 de todo el mundo proviene de fuentes antropogénicas. En comparación, dichas cargas están disminuyendo en América del Norte y Europa debido a la implementación de medidas efectivas de reducción de fósforo. La causa inmediata del aumento de la contaminación del agua es el crecimiento de las cargas de aguas residuales en ríos y lagos. Las fuentes actuales de contaminación más importantes varían de contaminante en contaminante. Las principales causas del aumento de la contaminación del agua son el crecimiento de la población, el aumento de la actividad económica, la intensificación y expansión de la agricultura, y el aumento de sistemas de alcantarillado con un nivel bajo o nulo de tratamiento.

La recolección de aguas residuales en el alcantarillado reduce el contacto directo de las personas con residuos y patógenos y, de esta forma, es una estrategia importante para proteger la salud pública. Sin embargo, la

7En este informe “lagos importantes de todo el mundo” se refiere a los cinco mayores lagos en términos de área superficial en cada una de las regiones definidas por el PNUMA en las “Perspectivas del Medio Ambiente Mundial” (África, Asia, Europa, América Latina y América del Norte).

LIV

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instalación de alcantarillas también ha concentrado la descarga de contaminantes en aguas superficiales y ha transferido el lugar del riesgo para la salud de las personas. La mayor fuente de contaminación patógena (cargas de bacteria coliforme fecal) en América Latina son las aguas residuales domésticas de alcantarillas, en África son los residuos domésticos sin alcantarillado, y en Asia son las aguas residuales domésticas de alcantarillas seguidas de cerca por los residuos domésticos sin alcantarillado. La mayor fuente de contaminación orgánica (cargas de DBO) en América Latina son las aguas residuales de alcantarillas, en África y en Asia es la agricultura de regadío. La mayor fuente antropogénica de contaminación salina (cargas de TDS) en América Latina es la industria, y en África y Asia la agricultura de regadío. Fuentes importantes de fósforo antropogénico en los lagos más importantes en América Latina son los residuos de ganadería y fertilizantes inorgánicos, en África son los residuos de ganadería, en Asia y Europa es el agua residual doméstica, residuos de ganadería y fertilizantes inorgánicos, y en América del Norte son los fertilizantes inorgánicos. Aunque la contaminación del agua es grave y está empeorando en América Latina, África y Asia, la mayoría de los ríos de estos tres continentes aún se encuentra en buenas condiciones, y existen excelentes oportunidades para detener la contaminación y restablecer la calidad de los ríos que necesitan mejorar.

En los puntos anteriores el foco fueron los diversos tramos de río en los que la calidad del agua es baja y continúa en deterioro. Pero la otra cara de la moneda es que muchos tramos aún no han sido contaminados: • Cerca de entre la mitad y dos tercios de todos los tramos de río (en América Latina, África y Asia) tienen un nivel bajo de contaminación patógena, • Más de tres cuartos tienen un nivel bajo de contaminación orgánica, y • Cerca de nueve décimos tienen baja contaminación salina. Aún es posible evitar que estos tramos limpios de río sean altamente contaminados. También es posible comenzar a restablecer la calidad de los tramos de río que ya se encuentran contaminados. Se pueden realizar muchas acciones para evitar el aumento de la contaminación y recuperar las aguas dulces contaminadas: 1. Monitorización — Se necesita una mejor comprensión sobre la intensidad y el alcance del desafío mundial de la calidad del agua. Para alcanzar dicha comprensión, se debe expandir la monitorización de la calidad del agua urgentemente, especialmente en los países en vías de desarrollo, y especialmente a nivel internacional a través del programa SIMUVIMA/Agua. 2. Evaluaciones — Se necesitan evaluaciones completas nacionales e internacionales del desafío mundial de la calidad del agua. Se necesitan estas evaluaciones para identificar los lugares prioritarios y las acciones que se deben realizar para tratar la contaminación del agua. 3. Nuevas y antiguas opciones técnicas y de gestión— Los países en vías de desarrollo tienen la oportunidad de no emplear el tratamiento tradicional de aguas residuales y también de hacer uso de nuevas y muchas más opciones técnicas y de gestión para gestionar la calidad del agua, entre ellas soluciones naturales. 4. Establecimiento de instituciones efectivas — Parte esencial de la gestión de la calidad del agua es el establecimiento de instituciones que promuevan acciones y superen las barreras para controlar la contaminación del agua. A continuación elaboramos las ideas anteriormente mencionadas: Qué se puede hacer: I. Monitorización No es posible realizar evaluaciones completas de la calidad mundial del agua debido a la baja calidad de la cobertura de recolección datos de calidad del agua de aguas superficiales en GEMStat, la única base de datos mundial de calidad de aguas. GEMStat tiene una densidad muy baja de estaciones en comparación con las densidades mínimas típicas de cerca de 1,5 a 4 estaciones por cada 10.000 km2 de área de cuenca hidrográfica en EE.UU. y Europa. En GEMStat, 71 de las 110 cuencas hidrográficas que poseen datos tienen una densidad de 0,5 o menos estaciones por cada 10.000 km2.

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La densidad promedio para América Latina es de 0,3 estaciones por cada 10.000 km2, para África de 0,02 estaciones8 por cada 10.000 km2 y para Asia 0,08 estaciones por cada 10.000 km2 en el periodo entre 1990 y 2010. La principal prioridad es expandir la cobertura espacial y temporal de las estaciones de monitorización en lugar de aumentar el número de parámetros recolectados en las estaciones existentes. Considerando los altos costos de la monitorización, es importante establecer prioridades respecto a los ríos con deficiencia de datos que se deben monitorizar primero. Los puntos críticos identificados en este informe pueden ser utilizados como referencia para decidir dónde expandir las iniciativas de monitorización. Las razones de la baja cobertura de recolección de datos son políticas, institucionales y técnicas. No obstante, existen muchas alternativas para mejorar la cobertura de recolección de datos de calidad del agua. Una alternativa para mejorar la cobertura es hacer uso de datos de teledetección. Los grupos actuales de datos cubren variables de calidad del agua esenciales para lagos, y en un futuro cercano estarán disponibles datos para ríos. Una ventaja de la teledetección es la amplia cobertura espacial y temporal de la recopilación de datos; las desventajas incluyen el número limitado de variables que se puede medir y el procesamiento de los datos brutos que se requiere. Otras opciones para mejorar la cobertura de recolección de datos de la calidad del agua son: (i) aumentar los esfuerzos para incorporar los datos nacionales y regionales a las bases de datos existentes, (ii) establecer grupos de trabajo de monitorización de agua dulce nacional para trabajar con sus contrapartes en otros países en la divulgación y uso de los datos de calidad del agua, (iii) consultar datos a través de proyectos científicos cívicos. La ciencia cívica tiene la ventaja adicional de involucrar a un público más numeroso en la eliminación dela contaminación del agua. Las iniciativas de recolección de datos también deben apuntar a hacer que estos datos estén disponibles en diversos lugares y puedan ser consultados a través de plataformas digitales como “UNEP Live”. Los datos también deben estar disponibles en diversos lugares en conexión con la monitorización y la implementación de los Objetivos de Desarrollo Sostenible. Qué se puede hacer: II. Evaluación Se necesita una Evaluación Mundial de Calidad del Agua a gran escala para evaluar el estado de los conocimientos sobre todos los aspectos esenciales de la calidad del agua, para establecer vínculos entre la calidad el agua y otros asuntos del Desarrollo Post 2015 tales como la salud y la seguridad alimentaria, y para identificar áreas de prioridad para estudios y acciones. La evaluación debe ser: • Multinivel — de cobertura mundial vinculada a valuacionese nacionales y evaluaciones temáticas. • Transparente y participativa — que implique una amplia gama de actores clave y científicos. La evaluación debe incluir: • Objetivos y temas que sean seleccionados en onjuntoc por las comunidades política y científica. • Un análisis de las opciones políticas para la protección y el restablecimiento de la calidad del agua. • Acceso amplio a los resultados poniéndolos a disposición en nuevas plataformas digitales (por ejemplo, “UNEP Live”). La evaluación también debe ser considerada una oportunidad de aumentar la capacidad técnica de los países en vías de desarrollo y su acceso a los más recientes resultados científicos. Qué se puede hacer: III. Opciones Técnicas y de Gestión Existen muchas opciones al alcance de los países en vías de desarrollo para evitar el deterioro de la calidad del agua de sus ríos y lagos. Muchas de estas opciones no existían o no fueron utilizadas por los países desarrollados cuando estos se enfrentaron a un similar deterioro de la calidad de sus aguas hace algunas décadas.

8Las áreas de tierra firme no se incluyen en el área continental.

LVI

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Las principales opciones técnicas son: (i) Prevención de la contaminación en la que se evite la fuente de contaminación del agua antes de que se transforme en un problema. (ii) Tratamiento de aguas contaminadas que constituye el enfoque tradicional para la reducción de las cargas de contaminantes antes de que sean descargadas en aguas superficiales. (iii) Uso seguro de aguas residuales reutilizándolas para el egadíor y otros propósitos. (iv) “Soluciones naturales” que impliquen la restauración y protección de ecosistemas tales como la reforestación de cuencas para reducir la erosión y las cargas sedimentarias en ríos o la restauración de humedales para eliminar contaminantes de los vertidos urbanos y agrícolas. Dentro de cada sección existen muchas ideas nuevas que no estaban al alcance de los países desarrollados cuando tuvieron que enfrentarse por primera vez a un deterioro similar de la calidad del agua hace tres o cuatro décadas. Entre estas nuevas ideas se encuentran: producción industrial más limpia, humedales artificiales, cero descargas de efluentes,y pago por servicios de ecosistema de cabeceras de río forestadas. Se necesitarán diferentes estrategias técnicas para controlar diversos tipos de contaminación del agua y fuentes de contaminación. Vale la pena intentar y agrupar estas estrategias en paquetes que puedan ser aplicados a diferentes cuencas hidrográficas. Por un lado, se mencionó anteriormente que las principales fuentes de contaminación difieren entre los diferentes tipos de contaminación del agua, lo que significa que una solución “de talla única” no funcionará para resolver el desafío mundial de la calidad del agua. Por otro lado, en todas partes del mundo surgen problemas similares con la calidad del agua incluso si los lugares y situaciones son diferentes. Por lo tanto, se podrían desarrollar diferentes paquetes de opciones técnicas que puedan ser usados en diferentes cuencas hidrográficas para lidiar con problemas similares. Qué se puede hacer: IV. Gobernanza e Instituciones Estudios de caso de diferentes cuencas hidrográficas señalan la importancia de una buena gobernanza e instituciones efectivas para gestionar la calidad del agua. Se descubrió que algunos importantes obstáculos para enfrentar los problemas de contaminación del agua incluyen: • La fragmentación de la autoridad dentro de una cuenca hidrográfica, • Falta de capacidad técnica, y • Falta de consciencia por parte del público sobre las causas de la contaminación del agua. Para superar estos y otros obstáculos, la experiencia de los estudios de caso demostró que una campaña pública de educación es una primera medida para obtener apoyo para el control de la contaminación del agua. Otra conclusión es que un Plan de Acción, acordado por todos los actores principales dentro de una cuenca hidrográfica, es un paso clave para establecer uncuerpo colaborativotal como las comisiones internacionales de los ríos Elba y Volta para desarrollar y ejecutar un plan de acción. En el caso del Elba, también se demostró que una institución nacional de gran alcance (la Comunidad de la Cuenca Hidrográfica del Elba) puede proporcionar una valiosa plataforma para obtener la cooperación de todos los actores nacionales principales dentro de una cuenca hidrográfica. El trabajo con el desafío mundial de la calidad del agua está directamente relacionado a muchas otras prioridades de la sociedad tales como la seguridad alimentaria y la salud. Por lo tanto, las acciones para proteger la calidad del agua deben estar insertas en el concepto más amplio de sostenibilidad, y ser parte de las iniciativas para alcanzar los Objetivos de Desarrollo Sostenible. Los estudios de caso señalaron que el desafío de la protección de la calidad del agua está interconectado con muchas otras tareas de la sociedad —el abastecimiento de alimentos, el desarrollo de la economía y el saneamiento seguro—. Por lo tanto, dentro de los próximos años será muy importante vincular las objetivos para la calidad del agua con otros objetivos de la Agenda Post 2015 y los nuevos Objetivos de Desarrollo Sostenible.

LVII

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LVIII

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A Snapshot of the World’s Water Quality: Towards a global assessment Towards Quality: Water World’s of the A Snapshot a global assessment Towards Quality: Water World’s of the A Snapshot Chapter 1–5 a global assessment Towards Quality: Water World’s of the A Snapshot Literature UNEP report UNEP report UNEP report UNEP report

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Buch_UNEP_hintere_Kapitel1504.indb 2 09.05.16 17:18 1 Introduction

1 Introduction

At the 1992 Earth Summit, freshwater was highlighted and support on mechanisms for protecting water in Agenda 21 as a topic of worldwide concern bodies and aquatic ecosystems through projects such (UN, 1992). Since then, the crucial role played by as the production of the Compendium of Water Quality freshwater in global development, global health, and Regulatory Frameworks: Which Water for Which Use in sustainability, have been highlighted many times (UN-Water, 2015a) and the International Water Quality and action has been called for in several international Guidelines for Ecosystems (UNEP, 2015c). summits. While a strong message emerged from Sources of good quality water for drinking and domestic these summits about freshwater in general, the same use, whether surface or groundwater, are fundamental cannot be said about the worldwide challenge of poor to human health. In some world regions between 70 water quality. For example, the Millennium Summit in per cent and 85 per cent of the population rely on 2000 produced the Millennium Development Goals surface waters as their source of drinking water (Morris (MDGs) (UN, 2000) which focused on urgently needed et al. 2003) although in some countries it can be 90 improvements to drinking water and sanitation but did per cent or more. Consumption of water containing not specifically call for improvements in water quality. pathogens or elements that are potentially toxic can Yet, adequate quantities of good quality freshwater are lead to health impacts ranging from discomfort to essential for human health, food security (particularly death (WHO, 2011). Pathogens in human sewage inland fisheries) and the aquatic environment itself. that contaminate surface and groundwaters used for Twenty years after Agenda 21, the United Nations drinking or food preparation, recreation or irrigation Conference on Sustainable Development, Rio +20, again of food crops, are responsible for many diseases, placed water at the core of sustainable development. especially diarrheal diseases such as cholera. Recent This time, the outcome document “The Future We estimates suggest that 58 per cent of total deaths from Want” (UN, 2012) recognised water as being linked to diarrhoea (which is amongst the top ten causes of several key global challenges and highlighted the need death worldwide) in low- and middle-income countries to reduce water pollution, improve water quality and are due to poor quality drinking water, together with reduce water loss. inadequate sanitation and hygiene (WHO, 2014b). At the United Nations Sustainable Development Although this figure has improved from the estimate of Summit in New York in September 2015, the General 88 per cent in 2000, water bodies contaminated with Assembly adopted 17 Sustainable Development Goals human excreta and used for other human activities (SDGs), which aim to build on the MDGs and complete (such as drinking, cooking and cleaning, recreation what they did not achieve (UN, 2015). Goal 6 “Ensure and irrigation) pose a serious threat to the health of availability and sustainable management of water the water users, especially women and children as and sanitation for all” (UN, 2015) specifically calls for articulated in Chapter 3. sustainable withdrawals, access to adequate quantity The essential services that aquatic ecosystems provide for all and an improvement in water quality by 2030. for human society, either directly or indirectly, were For the first time, there is an acknowledged need to identified by the Millennium Ecosystem Assessment protect aquatic ecosystems and to preserve ambient (2005a) and recently highlighted again in the World water quality. Progress towards this goal will need to Water Assessment Programme (WWAP) report be monitored and currently indicators for monitoring “Water for a Sustainable World” (WWAP, 2015). These ambient water quality are still being developed and essential services include water for drinking and agreed upon. UN-Water, the inter-agency coordination irrigation, purification of wastewaters, fisheries for mechanism for all freshwater and sanitation related food, hydroelectricity, flood regulation, wetland plants matters, is co-ordinating various actions within the UN for fuel and construction, and water and nutrient system that will contribute to the implementation of the cycling. Up until relatively recently, interest in water SDGs, including monitoring of water quality (through quality was focused purely on direct human uses GEMS/Water – see below), as well as providing advice with little effort being directed towards monitoring or

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maintaining water quality for the benefit of the natural Organic matter in sewage or in manure and food waste communities of aquatic organisms, i.e. ecosystems. is naturally degraded in water bodies by chemical But these ecosystems are important not only from the and microbiological activity (see Chapter 3). These ethical standpoint of conserving biodiversity, but also degradation processes use up the dissolved oxygen because they are an important source of food and (DO) in the water, causing stress for many aquatic livelihood for many people in developing countries. As organisms including fish species that require oxygen for noted in Chapter 3, inland fisheries are a major source respiration. The demand for oxygen in a water body is of animal protein in many parts of the developing used as an indicator of organic matter pollution through world. Poor water quality disturbs the balance of the biochemical oxygen demand (BOD) test. This test aquatic ecosystems, often resulting in changes in is widely used to determine the impact of sewage fish species and declines in valuable fish stocks. releases into rivers. Severe organic pollution, as it is Contamination with organic matter from domestic sometimes called, can lead to complete deoxygenation and food waste, and increases in nutrient levels from (anoxia), in which very few organisms can survive. agricultural activities, are two of the major threats to Low DO levels also lead to chemical reactions that inland fisheries, combined with reduced water levels result in the release or formation of other toxic and interruptions to migration routes by dams and compounds such as ammonia and hydrogen sulphide weirs (Welcomme et al., 2010; FAO, 2014). in sediments and bottom waters. Ammonia is also a What is causing water pollution? common component of excretion products and can be found in high concentrations in sewage. It is therefore Water quality is naturally influenced by the often measured in polluted water bodies because it is climatological and geochemical location of the water particularly toxic to fish (see Box 3.3). body through temperature, rainfall, leaching, and run- Agriculture and other land-based activities off of elements from the Earth’s crust. However, most surface water bodies around the world are also affected Intensification of agricultural production to meet to some extent by impacts from human activities, growing food demands leads to pressure on water particularly the discharge of waste products (including resources for irrigation and to degradation of surface sewage) or addition of sediments, salts and minerals water quality from run-off carrying fertilisers and with run-off from agriculture and urban settlements. pesticides from agricultural land. Groundwaters can Chapter 3 articulates the extent of this impact for key also be contaminated with agricultural chemicals water quality indicators. Even in remote locations, through infiltration. Sometimes the abstraction of water in lakes contains traces of toxic compounds water for irrigation substantially reduces available carried in the atmosphere from waste discharges in surface water volumes and contributes to declining industrialised regions. water quality by returning water that is contaminated with salts, fertilisers and pesticides. The increased levels Domestic and municipal wastewater of minerals and salts damage the ecosystem (Cañedo- Human sewage contains pathogens, organic matter, Argüelles et al., 2013) and make the water less suitable and chemicals used by people, such as pharmaceutical for other uses, particularly irrigation (see Chapter 3). products. Human and animal excreta can potentially One of the most studied and best understood impacts contain a variety of transmissible pathogens, such as on water bodies is the increase in nutrients arising viruses, bacteria, protozoa and worms. The occurrence from land-based activities resulting in eutrophication of these pathogens depends on geographical location and the associated changes in aquatic ecosystems, and the occurrence of the disease in the local both freshwater and coastal (Schindler, 2006; Smith population. Practically speaking, it is not possible et al., 2006). In most pristine water bodies, levels to monitor water for the presence of all potential of the nutrients nitrogen and phosphorus are low, pathogens, whereas it is relatively simple to detect arising only from the leaching of minerals or from the presence of faecal matter by the presence of decomposition of living matter. Higher levels are faecal coliform bacteria (see Chapter 3). Globally, such typically an impact of human activity, particularly indicators are used to indicate contamination by faecal fertiliser run-off from agricultural activities andthe matter and the possibility of pathogens being present, discharge of sewage effluents (see Chapter 3). The and they are an essential indicator for risks arising from resulting eutrophication enhances productivity, contact with surface waters and drinking water. which can have negative consequences for water use,

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such as growth of nuisance plants and algal blooms, compounds in the WHO Guidelines for Drinking-Water changes in ecosystem structure and fish species, and Quality (WHO, 2011). Practically speaking, only the deoxygenation when algal blooms decompose (Box 3.4; most toxic and persistent compounds are measured in Schindler, 2006). Rivers ultimately carry their burden water bodies on a regular basis, apart from in drinking of pollutants, including sediments and nutrients, to the water, because the range of possible compounds is coastal zone and, increasingly, eutrophication is being huge, the concentrations are usually low, and the detected in coastal waters (e.g. Borysova et al. 2005). techniques for measurement expensive (Petrovic, The first global assessment of water quality in 1988 2014). The availability of such data at a global scale is highlighted that eutrophication was already a global therefore sparse, even though for some countries it problem then (UNEP/WHO, 1988; Meybeck et al., is widely available (Hughes et al., 2012). Today, new 1989) and, with increasing demand for food production forms of toxic compounds are being evaluated for their and wastewater disposal over the last three decades, potential to reach the aquatic environment and to eutrophication is still a major water quality issue today lead to potential damage to aquatic systems or even (Millennium Ecosystem Assessment, 2005b). human health through consumption of contaminated Wastewater from many land-based sources including water (Corcoran et al., 2010). These new and emerging agriculture, industry and domestic sewage carry compounds include excreted and metabolised dissolved salts and minerals to surface waters. The pharmaceutical products, such as hormones and different classes of drugs. The range of potential concentration and nature of these dissolved salts, compounds that could be monitored is huge and such as chlorides and sulphates, varies according to currently there are few monitoring programmes that the source. However, in high concentrations they routinely include them. The water quality situation upset the natural chemical balance of the receiving with regards to these compounds should be dealt with water, leading to salinisation and making the water in future assessments. unfit for particular uses (especially industrial uses) and for sensitive aquatic organisms. This is sometimes Need for data and monitoring to support assessment called “salinity pollution”. Salinisation of freshwater is and to support the identification of solutions occurring at the global scale and can be detected by Most nations are concerned primarily with the quality the relatively simple measure of total dissolved solids of their own waters, except in situations where water (TDS) (see section 3.4). bodies cross national boundaries and international Industrial activities and emerging pollutants agreements or programmes have been put in place. Monitoring is often directed specifically towards the Social and economic development depends on safety of drinking water or control of waste discharges, access to adequate quantities of good quality water and is guided by national or local policy and legislation. for manufacturing and production processes, and With increasing environmental awareness in the the treatment and assimilation of waste products. 1970s it was realised that water quality at a global Some industrial processes, such as the production of scale was inevitably likely to deteriorate and a means pharmaceutical compounds, require very high quality of monitoring this over time was needed in order to water and others, such as paper production require define and set global priorities for protection of water large quantities. Meeting these needs in the future will resources. The 1972 Stockholm Conference on the be a major challenge if current levels of water use and Human Environment called for the establishment of degradation continue (WWAP, 2015). a global water monitoring programme and in 1978 As far back as the 1970s it was realised that the GEMS/Water (Global Environment Monitoring System discharge of waste products containing metals and for Water) was set up as an inter-agency programme chemical compounds was impacting the aquatic under the United Nations Environment Programme environment, particularly the aquatic food chain (UNEP), World Health Organization (WHO), World and predatory animals and birds. Many metals (e.g. Meteorological Organization (WMO) and United mercury, cadmium, arsenic) and most synthetic Nations Environmental, Scientific and Cultural organic compounds (e.g. PCBs, pesticides) are toxic Organization (UNESCO). The intention was to collect to living organisms, including people, at high enough global water quality data and to increase the capacity concentrations. This issue has been partly addressed of developing countries to undertake the necessary by the inclusion of guideline levels for metals and monitoring. In the 1980s a first attempt was made to

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use the GEMS/Water database to carry out a global pollution on inland fisheries and their connection to assessment of water quality. However, the inconsistent food security, iii) the impact of salinity pollution on spatial and temporal coverage of the data, together limiting water use for irrigation, and (iv) the impact of with large variations in the range of water quality human activities on the loading of nutrients to lakes. variables reported to the database meant that the first Because it is only a pre-study it is not feasible to cover global water quality assessment (UNEP/WHO, 1988; all parts of the world in the same detail. In particular, Meybeck et al., 1989) had to rely on the use of other the analysis of water quality in rivers concentrates on data sources, together with the results of special studies the continents of Latin America, Africa and Asia because published in the scientific literature. Nevertheless, the of the fewer assessments available about water quality assessment highlighted a number of water quality on these continents as compared to North America, issues that were occurring on a global scale, e.g. Europe or Australia. eutrophication, organic matter pollution from sewage As noted above, the report takes a combined data- and elevated nitrate in groundwaters (Meybeck et and model-driven approach, which makes best al., 1989) and which have been further specified in use of available information and compensates for later studies based on GEMS/Water data (e.g. UNEP the limitations of both approaches (see Chapter 2008). Today the situation is unfortunately very similar. 3). Observed data come from the UNEP Global But this report combines the limited amount of data Environment Monitoring System for Water (GEMS/ with modelling to successfully obtain a first picture of Water), and modelling results from the global the water quality situation in rivers throughout Latin WaterGAP/WorldQual model. America, Africa, and Asia. Moreover, there are now To describe and analyse the world water quality monitoring programmes in some world regions that are situation, the “DPSIR” conceptual framework is used, intended to track the long-term changes in these issues which divides different aspects of a system into at the river basin scale, to identify new issues and to linked “drivers”, “pressures”, “states”, impacts” and provide the information that will assist in identifying “responses”. This framework is used to structure the solutions (e.g. Liska et al., 2015 for the Danube River material in the report, but is not referred to explicitly basin). It has now been 27 years since the first and only in the report. global water quality assessment. The time is overdue The report is structured into five chapters, including to again assess where the world stands with regards to this Introduction. Chapter 2 evaluates the availability the quality of its freshwaters. of global data and gives an example of use of these How to read the report data for in-stream water quality analysis; Chapter 3 This report addresses the need to assess the current gives first estimates of water quality problems on three world water quality situation so as to identify the scope continents using the combined data-model approach and scale of the “global water quality challenge”. This is to determine the scale of the water quality challenge, a pre-study of a full assessment. The first objective of to set priorities for action in hot spot areas, and for this pre-study is to provide some of the building blocks monitoring; Chapter 4 presents eight case studies of for a full-scale world water quality assessment. The water quality issues at the basin level that illustrate second objective is to present a preliminary estimate the wide range of water quality challenges and how of the water quality situation of freshwater ecosystems they are being met; and Chapter 5 outlines the wide in the world, with a focus on rivers and lakes on three range of options to meet the water quality challenge continents. and raises critical issues that need to be considered to Since it is a pre-study and not a full assessment the scope meet this challenge. of the report is limited. It focuses on a small number of As a whole, the report addresses especially persons important water quality problems in surface freshwaters interested in the methodology proposed, the – pathogen pollution, organic pollution, salinity exemplary results presented and lessons learned – in pollution and eutrophication, and their relevance to organisations dealing with global water related issues, human health, food security, and livelihoods. Likewise in water authorities worldwide or in academia – by it concentrates on a small, but important set of impacts providing a sweeping view of some important aspects of these water quality problems: i) the threat posed by of the global water quality challenge and pointing the pathogen pollution to people coming into contact with way to a needed full assessment of the world water contaminated surface waters, ii) the impact of organic quality situation.

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2 State of observational knowledge

Aim of this chapter • To review the availability of water quality data at the international level and suggest how to make more data available. Main messages • Data are essential for developing, monitoring and evaluating water resources management strategies • New technologies and monitoring strategies will simplify data acquisition and strongly expand data availability in the near future • The Global Environment Monitoring System (GEMS) is a suitable platform to aggregate global water quality data • At present, the GEMStat database is a critical source of data because it has sparse spatial and temporal coverage and its data holdings do not have a high level of coherence. • Further developing and strengthening GEMS/Water, and giving it clear institutional objectives and mandates, will increase the global availability of water quality data and enable a reliable global assessment of water quality. • The hot spot areas of pollution identified in this report can be used as input in deciding where to expand monitoring efforts

2.1 Why do we need global data?

Understanding the global and regional patterns of regarding hydrology, sampling location, analytical water quality, both in the past and present, is necessary methodologies and quality assurance. if we are to come to grips with risks to water security Currently, water quality monitoring programmes and and ways to minimize these risks. Furthermore, this available data bases are usually based on water quality knowledge is a basis for future projections of water samples collected at specific times and locations and quality under the influence of global change. their subsequent laboratory analysis. In the near The observational data needed for this understanding future it is expected that these traditional techniques must capture the temporal dynamics of water quality will be complemented by remote sensing data, which components and have to be coherent over local, will become available at spatial resolutions covering catchment and global spatial scales. The selection of whole river networks and lakes of various sizes. The key water quality parameters is an equally important next generation of hyperspectral sensors will provide task. They should cover the major characteristics of the information that can be linked to a wide set of water freshwater system including its physical characteristics, quality parameters and that will require ground oxygen balance, nutrient status, mineral composition truthing of the spectral signals. and presence of specific pollutants. They should also Furthermore, autonomous water quality monitoring reflect the influence of anthropogenic pressures and techniques are developing rapidly and will allow for impacts. new approaches for setting-up large scale monitoring In order to retrieve reliable information from large networks. Photosensors have been miniaturised, and data bases with data driven methodologies (such as dropped in price, and are now widely available for analytical statistics, time series or spatial analysis) popular electronic devices such as smartphones. Due there is a need for complementary meta-information to this development, water users and citizens could

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be much more closely involved in future monitoring significantly with regard to methodologies, sources efforts. Therefore, future data bases for water quality of information and therefore spatial and temporal will build on the existing systems, but may expand coverage.

2.2 What data are available from GEMS/Water?

2.2.1 GEMS/Water Programme and GEMStat activities. In general, the station density of surveillance The GEMS/Water Programme, established in 1978, monitoring has a minimum of one station per 2,500 is the primary source for global water quality data. km² within a river basin, equivalent to four stations Today, GEMS/Water consists of several entities1 and is per 10,000 km². At these stations, the monitoring oriented towards building knowledge on inland water frequency for physico-chemical parameters (e.g. quality issues worldwide. Key activities include data temperature, pH, nutrients, salinity, and oxygen) is collection, research, assessment and capacity building. four times per year. The station density and frequency The twin goals of the programme are to improve of measurements for “operational” monitoring (for water quality monitoring and assessment capacity in assessing the current status and short term changes of participating countries, and to determine the state and waterbodies) could be much higher in order to achieve trends of regional and global water quality.2 an acceptable level of confidence and precision. The data from participating countries are made In the United States, a monitoring programme in the available within the GEMS/Water online database, State of South Carolina has a station density of 3.8 3 GEMStat. Formerly located in Canada, the responsibility stations per 10,000 km² (U.S. EPA, 2003) and another of GEMStat moved to the Federal Institute of Hydrology in the State of Wisconsin has an average density of 1.6 2 4 (BFG) in Germany in 2014. At present, GEMStat includes stations per 10,000 km (Anon, 1998) . data from more than 100 countries, and contains Compared to the above examples which range from approximately five million entries for lakes, reservoirs, around 1.5 to 4 stations per 10,000 km2, the densities wetlands and groundwater systems. of stations in the GEMStat data base (Figure 2.1) are very low. In GEMStat, 71 out of the 110 river basins 2.2.2 Review of data availability (status 2014) with data have a density of 0.5 stations per 10,000 km² or less. Only 57 countries report data in the time period The availability of data in GEMStat was assessed for of 1990 to 2010. The average density for the Latin a selection of parameters of particular importance to American continent is 0.3 stations per 10,000 km², the status of water quality of inland freshwaters. In for Africa 0.02 stations per 10,000 km², and for Asia particular the spatial and temporal coverage of data 0.08 stations per 10,000 km² during the time period was evaluated. A complete list of the data available between 1990 and 2010. Against this background, it is for this study (river basins, stations per river basin, of course difficult to obtain a representative and valid number of measurements, number of measured assessment of the water quality for an entire river parameters, time frame) is given in Appendix A. The basin. Furthermore, the selection of water quality station densities and temporal coverage of data on the parameters measured was not consistent, and the river basin scale are depicted in Figure 2.1. Overall, frequency of measuring water quality parameters is data is available for some 110 river basins worldwide very variable. Depending on the parameter, the range for the time period of 1990 to 2010. Data from one is from 1 to 12 measurements per year, parameter and third of these river basins are older than 10 years. station. The average monitoring frequency for Latin To judge the adequacy of the density of stations, other America and Africa is 4, and for Asia 5.5 measurements water quality monitoring programs in the world can be per year, parameter and station. Because of the huge considered. For example, according to the European data gap and the high variability of data metrics, a valid Water Framework Directive – WFD (European comparison of water quality status or trends between Commission, 2000), the legally binding instrument for catchments is not feasible with the current data base. water policy in Europe, “surveillance monitoring” aims A proposal on how to further develop and improve the to evaluate long-term changes in natural conditions utility of the GEMStat data is described in Box 2.1. and changes resulting from widespread anthropogenic

1The GEMS/Water Global Program Coordination Unit in Nairobi, Kenya, the GEMS/Water Capacity Development Centre at the University of Cork, Ireland and the GEMS/Water Data Centre at the Federal Institute of Hydrology, Koblenz, Germany. 2http://www.gemstat.org 3These sites target the most downstream access of each of the Natural Resource Conservation Service (NRCS) 11-digit watershed units in the state, as well as 8 the major waterbody types that occur within these units. For example, if a watershed unit ends in estuarine areas at the coast, integrator sites are located in both the free-flowing freshwater portion and the saltwater area. 4One station with a disproportionally large drainage area was left out of the average of the 43 recommended stations.

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Data availability based on GEMSStat (temporal coverage) No. of stations/10,000 km2

Figure 2.1: Temporal coverage (grey shading) and station density (size of circles) of GEMStat data (Data source: GEMStat, 2014; GIS data source: GRDC, 2007).

Box 2.1: Utility of GEMS data on the way towards a world water quality assessment Water quality data of GEMStat should be used together with robust, valid, reliable and comparable methods to comprehensively assess global water quality. Using the concentration of a specific parameter in a river basin, water quality could be classified for given levels or ranges of concern. These data need to be clearly linked to the functionality of riverine ecosystems and food security issues with respect to water quality requirements for freshwater fish and invertebrates such as crayfish or mussels. It is important to know baseline concentrations of water quality parameters so that temporal trends of water quality can be tracked. A trend analysis could indicate an improvement, deterioration or stagnation in the quality of water for a specific time period. As a simple example, thresholds were selected to classify the water quality of river basins in two categories, above and below “levels of concern”. While thresholds were mainly derived from established water quality requirements of a healthy fish fauna, compliance with the levels of concern could also be interpreted as lower risk for food security. For the analyses of trends, and taking into account the sparse temporal coverage of data, median concentrations of the water quality parameters were calculated for the decades 1990 to 1999 and 2000 to 2010. Non-parametric statistical tests indicated whether the differences between the time periods were insignificantly or significantly changing (increasing or decreasing). The methods employed for the analysis took into account the heterogeneity of GEMStat data by focusing on robust metrics and are therefore widely applicable. The following map (Figure 2.2) visualises an example of a risk classification for the parameter dissolved oxygen in river basins where data are available. The top map indicates whether the mean oxygen concentration of all measurements in a river basin under consideration are above or below an example threshold “level of concern” (7 mg/l)5, and the bottom map shows the trend of data. Fewer river basins appear in the trend analysis in the lower map because several river basins were lacking data for either 1990–1999 or 2000–2010. Dissolved oxygen concentrations (1990-1999) were at or below the level of concern (7 mg/l) at various stations in Latin America, Asia and India. A decreasing trend of dissolved oxygen was observed in stations in Eastern Europe and India.

5“Level of concern” in this chapter is used to mean the pollutant concentration above (or below) which significant negative impacts occur. In this report these concentrations are derived from water quality standards from official sources such as government departments or UN agencies. This level of concern is derived from guidelines for temperate zones. The potential impacts have to be evaluated in the framework of regional climatic and other conditions. 9

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Oxygen conc., median Oxygen conc. < 7 mg/l Oxygen conc. > 7 mg/l

Decreasing trend No or increasing trend

Data availability based on GEMSStat (temporal coverage)

Figure 2.2: Example of risk classification for dissolved oxygen by comparing measured levels with a level of concern (above), and decadal trends (below) for major river basins. Data source: GEMStat, 2014. Light grey river basins: data available until 1999. Dark grey river basins: data available until 2010.

2.3 Can data from the scientific literature help fill the data gap?

One option to supplement the sparse data in The conclusion was that the data published for Africa GEMStat is to use data from the scientific literature. are very dissimilar and disparate. Most published To assess the feasibility of this option 120 reports and data are aggregated over long time periods and/or publications on water quality in Africa were reviewed. over several sampling stations. Furthermore, specific To judge the suitability of data in these publications locations of sampling stations are usually not available for assessments the following attributes were noted: and the selection of parameters was restricted. availability of precise sampling location (GIS-data), Overall, they were not comparable with GEMStat data temporal and spatial coverage of data, adequacy of which are based on monitoring results and raw data. information on analytical methods, and the number of On the other hand, data from scientific literature can water quality parameters. For this, only publications be used to supplement GEMStat data for the purpose were studied that provided measured data. of model testing and preparing model inputs and they are used for this purpose in Chapter 3.

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2.4 What is the potential of remote sensing?

Part of the solution to the urgent global data gap is Most efforts at collecting water quality data from to derive water quality information from remote space-born remote sensing platforms have focused sensing products. Satellite sensors potentially offer on the oceans and coastal areas rather than rivers and reproducible and globally consistent earth observation lakes. Collecting and interpreting data of inland waters data with a high scientific standard (Bukata, 2005). is a big challenge because of the higher complexity of Therefore, remote sensing can provide data where it is the optical signal from freshwaters and the relatively too expensive to monitor water quality or at locations smaller dimensions of many inland surface water that are remote. bodies and river networks. Rivers often exhibit Space-born remote sensing can provide data of turbidity levels of one or more orders of magnitudes selected water quality parameters at spatial scales higher than coastal or marine environments at a high and with temporal resolutions that exceed the density temporal dynamics. Furthermore, humic and organic of ground based monitoring stations by several orders substances interfere spectrally with the measurement of magnitude. Examples for the next generation of parameters such as turbidity and transparency of satellite missions are: hyperspectral HyspIRI (Olmanson et al., 2014). Moreover, to acquire data (Hyperspectral Precursor and Application Mission, for smaller rivers and streams, a much higher spatial launch in 2010, pixel resolution 60x60m, combination of resolution is needed than for oceans or coastal areas. hyperspectral and thermal sensors), the multispectral However, few available sensor data with a sufficiently missions (Copernicus mission, Sentinel 2 & 3, launch in high spatial, spectral and radiometric resolutions 2016) and the hyperspectral Environmental Mapping became available recently, such as Sentinel-2 (10-20 m) and Analysis Program (EnMAP) starting in 2018. The and Worldview-2/3 (1–2 m) data, in combination with latter will have a pixel resolution of 30 m x 30 m and robust physics based retrieval algorithms reflecting a scanning capacity of 30 km x 5,000 km per day the complex interplay of extreme concentration following sun synchronous orbits (EnMAP, 2015). This ranges and applicable for a wide range of previous and would allow for the comparative analysis of a given upcoming satellite sensors (Heege et al., 2014) . location on the earth’s surface within four days. For water quality assessments, the potential usability Because the optical sensors detect reflected sunlight, of remote sensing data of lakes is better than that of parameters which have an effect on the optical river networks. Because of larger surface areas and properties of water can be deciphered. For this typically higher clarity of lakes, remote sensing data purpose, the spectral signatures have to be analysed are available from a larger set of satellite missions, with optical models that depict the relationship including Sentinel-2, Landsat, and MODIS, covering between the reflectance and the concentration of a wider range of spatial resolutions or spectral relevant water quality constituents (ZhongPing, 2006). information. Currently, remote sensing platforms can Remote sensing platforms can identify and quantify provide diverse information about lake characteristics, several key water quality indicators: especially clarity, transparency, coloured dissolved organic matter, chlorophyll and other algal pigments • sea surface temperature, (e.g. Matthews et al., 2010, Chawira et al., 2013). • chlorophyll a (an indicator of the concentration of A great advantage of space-born remote sensing is algae), that it can provide a long-term, simultaneous record of • various ecologically important phytoplankton water quality in water bodies over large regions. For groups including potentially toxic algal blooms in example, Landsat images show the “clarity” parameter eutrophic coastal and inland waters, of more than 10,000 lakes in Wisconsin (USA) for a time • secchi depth / transparency, period of more than 20 years (Olmanson et al., 2014). • coloured dissolved organic compounds, Despite the many advantages of remote sensing • turbidity, different fractions of suspended mineral acquisition of water quality data, the following and organic particles, and limitations should be kept in mind: • sediment dynamics in estuaries, tidal flats, • The water quality parameters that can be wetlands, and mangrove forests. measured by remote sensing are small in number

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and limited to those which influence the optical for lakes e.g. by the EU Glass (Global Lakes Sentinel properties of the water. Services) project (GLASS, 2016; EOMAP, 2016). • The application of remote sensing for water • A prerequisite for successful ground-truthing quality assessments of rivers is further limited by is the availability of good quality surface water the spatial resolution and spectral information of quality measurements on high spatial and the satellite missions in place and the complexity temporal resolution. Thus an aquatic sensor of the optical properties of running waters. network is required providing systematically • The potential of remote sensing for water quality monitored water quality parameters that can be assessments of lakes is higher than that of stored in global databases and made accessible rivers because of their larger size and the lower for calibration and validation of remote sensing complexity of water properties and conditions. data. • Water quality parameters such as chlorophyll-a • Future satellite-born remote sensing platforms will and algae bloom indicators can be directly derived have higher spatial resolutions and hyperspectral from remote sensing data. Other water quality optical signals and will therefore be much more information requires models that convert spectral applicable to the assessment of inland waters. signals from remote sensing platforms to water However, it is important to combine this new constituents. Empirical models require ground- generation of satellite data with ground-based truthing of remote sensing with ground-based measurements (Wireless Ad-hoc Sensor Networks measurements, while physical based models for Environmental Monitoring; Mollenhauer et al., derive optical properties also harmonized and 2015) so that the greatest value can be derived independent of in-situ measurements, as proven from these data.

2.5 How can more data be made available?

1. Incorporating existing national and regional monitoring data GEMS/Water will support the rollout of the IRIS by working with countries to further improve the spatial Following technological advancements and legal and temporal coverage of their water quality data. obligations, more and more countries are providing Provided that the IRIS will be adopted by countries, it their monitoring data publicly and online. However, this could become a key component in providing access to is mostly limited to developed countries with a strong selected national water quality monitoring data. technical focus. Furthermore, most of these countries have developed their own data exchange formats and 2. Setting up national freshwater monitoring working access methods that complicate transfer of data into groups GEMStat. In order to promote the interoperability of The current GEMS/Water networking and data data on the international scale, members of the joint collection strategy is based on the network of National WMO/OGC Hydrology Domain Working Group are Focal Points (NFPs), which have the responsibility to standardizing open data exchange formats and web facilitate the data flow between GEMS and national services such as WaterML2 and Sensor Observation states. However, frequent personnel changes at the Services. These steps will lay the foundations for NFPs hamper communication and data flows. One a globally distributed water resources information approach to overcome this barrier is to set up national system. GEMS/Water is not only aiming to support the freshwater monitoring working groups including standardisation process, but also to implement these governmental and scientific representatives who standardised formats and services at the national and provide a link between national monitoring activities sub-national scale to enhance data flows. and regional and global assessment programs. On the UNEP is currently developing the Indicator Reporting regional level, newly established GEMS/Water regional Information System (IRIS), a web-based platform that hubs (as recently set up in Brazil) can support the allows countries to share their environmental datasets, maintenance and extension of the Global Monitoring derive indicators and produce reports. Starting in 2015, Network and increase the exchange of data.

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3. Raising awareness with political instruments Observations has supported the development On the political level, UNEP and other UN-Water of algorithms to derive water quality data from partner organisations can increase awareness of water optical satellite imagery. As noted above, physical quality issues and gaps in water quality monitoring constraints and the limited spatial resolution of the coverage. Declarations such as Resolution 1/9 of satellite sensors restrict their use to a subset of water the United Nations Environment Assembly on water quality parameters (turbidity, total suspended solids, quality data exchange help to further improve data chlorophyll a) in lakes and other large freshwater availability. bodies. However, recent and future satellite missions such as Sentinel 2 with their improved spatial and 4. Retrieving data from citizen science projects and temporal resolution will enable the development of remote sensing based water quality data new algorithms that cover rivers and smaller inland New data sources from citizen science and remote water bodies. GEMS/Water is supporting this work sensing are becoming increasingly available and could by coordinating the collection of calibration and supplement governmental monitoring data (Box 2.2). validation data by the network partners with the The recently established Water Quality Community aim of creating operational remote sensing water of Practice uunder the “Integrated Global Water quality data services in collaboration with major space Cycle Observations” theme of the Group of Earth agencies.

Box 2.2: What is Citizen science? Citizen science is the practice of public participation and collaboration in scientific research in order to further knowledge. Through citizen science, people share and contribute to data monitoring and develop and expand collection programmes. Collaboration in citizen science involves scientists and researchers who develop and coordinate the programme and unpaid volunteers such as students, amateur scientists, or teachers. One example is Volunteer Water Quality Monitoring within the National Water Resource Project at the Universities of Wisconsin and Rhode Island in the United States.6 The goal of this project is to expand and strengthen the capacity of existing extension volunteer monitoring programmes and support development of new groups. This project includes the training of volunteers in monitoring water quality and developing internet and web-based tools for data management. In 2005, this project engaged 8,600 trained volunteers in monitoring lakes, wells, rivers, estuaries and beaches. In total, the project involves 30 separate collaborative programmes in 30 different states. Local and regional programme coordinators are responsible for the expansion of the programme. Another example is the development by the Delft University of Technology of new mobile sensing methods for water quality monitoring for use in citizen science projects. Delft is developing “indicator strips” as a convenient and practical way for volunteers to collect water quality data.7 A third example is the “World Water Monitoring Challenge” (WWMC) run by Earth Echo International, an environmental education organisation in collaboration with the Water Environment Federation and the International Water Association. As part of this program, volunteers are encouraged to test the quality of their local waterways and share their findings. To facilitate this, the WWMC sells individual and classroom water-testing kits for measuring temperature, acidity (pH), clarity (turbidity) and dissolved oxygen. Each kit contains an informative instruction book and enough reagents to repeat up to 50 tests. The location of stations, data and further information are made accessible to the public on an interactive web site.8

5. Setting priorities for monitoring hot spot areas identified in Chapter 3 for pathogen, Considering the high costs of monitoring, it is organic and saline pollution can be used as input in important to set priorities for collecting field data. The deciding where to expand monitoring efforts.

6http://www.usawaterquality.org/volunteer/ 7http://www.citg.tudelft.nl/en/about-faculty/departments/watermanagement/sections/water-resources/leerstoelen/wrm/research/all-projects/msc-research/ current-msc-research/application-of-citizen-science-and-mobile-sensing-in-water-quality-monitoring/ 8http://www.monitorwater.org/default.aspx 13

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3 Water pollution on the global scale

Aim of this chapter To gain a global overview of water quality problems in the surface waters of three continents. Main messages • A “combined data driven/model driven approach” is used to assess water quality on three continents and make the best use out of both measurement data (GEMStat) and modelling results (WorldQual). • Severe pathogen pollution already affects around one-third of all river stretches in Latin America, Africa and Asia. The number of people at risk to health by coming into contact with polluted surface waters may range into the hundreds of millions on these continents. Among the most vulnerable groups are women and children. • Severe organic pollution already affects around one-seventh of all river stretches in Latin America, Africa and Asia and is of concern to the state of the freshwater fishery and its importance to food security and livelihood. Countries reliant on inland fisheries as a food source should be vigilant about increasing organic pollution. Groups affected by organic pollution include local poor rural people that rely on freshwater fish as a main source of protein in their diet and poor fishers that rely on the inland fishery for their livelihood. • Severe and moderate salinity pollution already affects around one-tenth of all rivers in Latin America, Africa and Asia and is of concern because high salinity levels impair the use of river water for irrigation, industry and other uses. • Anthropogenic loads of phosphorus to the majority of major lakes are significant and may cause or accelerate eutrophication and disrupt the natural processes of these lakes. Most of the largest lakes in Latin America and Africa have increasing phosphorus loads. • The immediate cause of increasing water pollution is the growth in wastewater loadings to rivers. Different pollutants have different predominant sources. The ultimate drivers of increasing water pollution are population growth, increased economic activity, intensification and expansion of agriculture, and increased sewerage with inadequate treatment.

3.1 Introduction: A combined data and modelling approach

The water quality of the world’s rivers and lakes and trends in water pollution worldwide with a focus is undergoing important changes. As described in on Latin America, Africa and Asia. It also describes the Chapter 1, water quality has markedly improved combined data-driven and model-driven approach in many developed countries, although some used to obtain these estimates. The methodology problems persist such as eutrophication and water takes into account two major factors: First, that contamination by micropollutants and heavy metals. a considerable amount of measurement data is Meanwhile, in developing countries the tendency necessary for the assessment of three continents, seems to be towards increasing water pollution but an adequate amount of data is not available as urban populations grow, material consumption from the GEMStat database (as noted in Chapter 2). increases and the volume of untreated wastewater Nevertheless, GEMStat is the most comprehensive volumes multiplies. This chapter examines the extent data set available and should be exploited in any

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assessment. Secondly, great progress has been made the “WorldQual” model. WorldQual is a computational over the last fifteen years in modelling global and scheme for simulating water pollution loadings to continental water resources (e.g. Sood and Smakhtin, rivers and key water quality parameters in rivers 2015) and advancing the assessment of water around the world (See Appendix B). WorldQual is part resources in ungauged or poorly-gauged river basins of the WaterGAP modelling framework which has (Sivapalan et al., 2003). Therefore, modelling results been used for over a decade to estimate hydrological are used to fill in the data gaps in the GEMStat data characteristics of rivers worldwide (Alcamo et al., base. The combined data-driven and model-driven 2003; Flörke et al., 2013; Müller Schmied et al., 2014; approach (Figure 3.1) makes the best use out of both Schneider et al., 2011; Verzano et al., 2012). measurement data and modelling results and is used iii. After testing and calibration, WorldQual is used to throughout Chapter 3: comprehensively compute water quality data. This i. GEMStat data are used for a preliminary analysis of includes data-sparse areas and during time periods the water quality situation of each continent. Since not covered by GEMStat (See, for example, Figure there are large spatial and temporal gaps in these data 3.1). In this way, WorldQual acts as a tool to fill in the they were used in aggregate form to compute the gaps of the GEMStat data. WorldQual calculations statistical occurrence of different levels of pollutants. provide a detailed picture of the spatial and temporal Results from this statistical analysis are presented as distribution of water pollution on the three continents. frequency diagrams and “box-and-whisker plots” in iv. Hot spot areas identified through this approach can this chapter (see Figure 3.2 for example). then be used as input in deciding where to expand ii. GEMStat data are used together with additional monitoring efforts. data from the scientific literature to test and calibrate

Data-driven analysis Model-driven analysis

Use GEMS data Test model for preliminary GEMS Data with data analysis GEMS data

Apply model to generate data, including data-sparse areas

Use measurement data Use model data to assess for computing statistical spatial and temporal distribution of water quality distribution of water quality on continental scale on continental scale

Figure 3.1: The “combined data-driven/model-driven” approach of this pre-study.

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3.2 Pathogen pollution and the health risk

3.2.1 What health risks are related to polluted While the international community has goals for water? reducing the number of people exposed to unclean Water is obviously crucial to human health. The WHO drinking water, less attention has been paid to another advises that at least 7.5 litres per day per person are important route through which people are exposed necessary to meet “the requirements of most people to pathogens, namely through direct contact with under most conditions” and at least another 20 litres polluted rivers, lakes and other surface waters (WHO, per day to cover basic hygienic needs (WHO, 2015a). 2003). In this report, particular attention is paid to this Of course, the quality of this water must also be high route. The poor in rural areas of developing countries to avoid diseases. UNICEF (2008) estimates that 3.4 often use surface waters for bathing, for washing million people die each year from diseases associated clothes, as a source of cooking water and sometimes with pathogens in water, including cholera, typhoid, for drinking water. In both developing and developed infectious hepatitis, polio, cryptosporidiosis, ascariasis countries surface waters are used for recreational and diarrhoeal diseases (Stanwell Smith, 2002; WHO, bathing, for fishing and as a water supply for irrigation. 2014b; WHO, 2008; WHO, 2006). Worldwide about 4 Many different types of pathogens in water, including billion cases of diarrhoea are caused each year by the protozoan, parasites, bacteria and viruses, cause ingestion of water contaminated by faecal matter, as diseases. Since it is too costly to measure all types well as by inadequate sanitation and hygiene (WHO, of pathogens everywhere, most monitoring studies 2014b), and of these cases 1.8 million are fatal. of polluted water focus on one or a few types of Worldwide more than 40 million people were treated indicator organisms that suggest the presence of for schistosomiasis in 2013 (WHO, 2015b) and as many pathogens. Here one of the most common indicators as 1.5 billion people are infected with soil-transmitted is used, “faecal coliform bacteria”. Although most helminth infections (WHO, 2015c). All of these faecal coliform bacteria are in themselves not diseases are largely excreta-related and many of them harmful, they are associated with faeces of humans are due to the presence of human waste in water. and animals. Moreover, high levels of these bacteria are usually correlated with the presence of dangerous How do people get exposed to dangerous pathogens pathogens (WHO, 2001; Savichtcheva & Okabe, 2006). in water? An obviously important route is by drinking Several countries have acknowledged the connection contaminated water. Recognizing the importance of between faecal coliform bacteria and health risks by the public health threat of drinking unclean water, the setting limits for faecal coliform bacteria in their water international community has been striving to reach bodies (Appendix B). the Millennium Development Goal of halving the number of people without access to a safe drinking To assess the level of pathogen pollution, it is necessary water supply by 2015. As a result of these efforts, 2 to refer to a benchmark for safe and unsafe faecal billion people have gained access to safe water since coliform bacterial levels. Benchmarks used in this 1990 (WHO/UNICEF, 2014a; WHO/UNICEF, 2015). A study are shown in Table 3.1. The boundaries of these new set of international objectives, the “Sustainable classes are derived from the water quality standards Development Goals” include new ambitious objectives of 17 countries (Appendix B). for clean water and health (UN, 2015b).

Table 3.1: Classes of pathogen water pollution according to river concentrations of faecal coliform bacteria assigned in this report. Concentration is expressed in conventional units of “coliform-forming units per 100 millilitres” (cfu/100 ml). Based on water quality standards of 17 countries listed in Appendix B.

Faecal coliform concentration Water pollution class Description (cfu/100 ml) Generally suitable for contact Low pollution x ≤ 200 (including, e.g. swimming and bathing) Only suitable for contact during irrigation and Moderate pollution 200 < x ≤ 1,000 fishing activities, but not for other contact

Severe pollution x > 1,000 Generally unsuitable for contact

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3.2.2 What is the level of pathogen pollution? about one-quarter of all river stretches, are in the GEMStat analysis severe pollution class. For Africa, the estimate is around 200,000 to 343,000 km, or around one-fifth to Since the data from GEMStat are too sparse to analyse one-quarter of its river stretches, and for Asia around pathogen pollution in spatial or temporal explicit 493,000 to 793,000 km, amounting to about one-third details (see Section 2.2.2) they were consolidated into to one-half of its entire river stretches. general statistical distributions on a continental basis for the period 2000 to 2010. (Table 3.2 and Figure Another way of judging the intensity of pollution is 3.2). The median concentration of faecal coliform to estimate the number of months in a year in which bacteria in African rivers based on a sparse number of severe pollution occurs. In general, the higher the measurements (N=215) is 1,500 cfu/100 ml. Therefore, frequency of high pollution levels, the greater the it is considerably higher than the severe pollution level potential threat to people who come into contact (Table 3.1) derived from the national water quality with surface waters. Figure 3.4 shows the frequency standards listed in Appendix B. The medians for Latin of months per year in different river stretches in which America (N = 1,725) and Asia (N = 4,131) are a factor of severe pollution levels occurred from 2008 to 2010. ten lower and, therefore, in the low pollution class. In Here, river stretches with severe pollution in six or Africa, about 50 per cent of all measurements exceed more months each year are considered “hot spot the severe pollution level of 1,000 cfu/100 ml, in areas”. These include river stretches particularly along Asia and Latin America about 25 per cent (Figure 3.2, the western and eastern South American coastlines, right). Therefore this sparse data set indicates that a in North Africa, the Middle East, and southern and substantial fraction of river waters is polluted. eastern Asia. Modelling analysis Also of interest are the temporal trends in river pollution from 1990 to 20102. As will be seen in Building on the analysis of the GEMStat data, the results Section 3.2.4, loadings of faecal coliform bacteria have from the modelling analysis provide a more detailed increased over the last two decades on the average in picture of the spatial and temporal distribution of Latin America, Africa and Asia. Apparently, although faecal coliform bacteria on the three continents. sanitation coverage has increased and treatment levels Figure 3.3 shows an example of average monthly levels have improved in some countries (UNICEF, 2014), the 1 of faecal coliform bacteria from February 2008–2010 efforts being made were not sufficient to reduce faecal according to the water pollution classes in Table 3.1. coliform loadings reaching surface waters (see Box 3.2). Stretches of rivers in the “severe pollution” class are One consequence is that in-stream concentrations marked in red and occur on all continents, especially of faecal coliform bacteria have increased over this in Asia with many river stretches in southwest and period throughout almost all of Latin America (59 eastern Asia. This is in agreement with Evans et al. per cent), Africa (63 per cent) and Asia (69 per cent) (2012) and UNEP (2010) who emphasised that faecal (Figure 3.5). In total, 64 per cent of the river stretches coliform pollution of rivers from domestic sources is a on these three continents have an increase in faecal major problem in Asia because of inadequate access coliform bacteria. A subset of these river stretches to sanitation and connections to sewers. with an “increasing trend of particular concern” However, it is not advisable to focus on results from a amount to 25 per cent of the total kilometres of rivers single month because it is well known that the level of in Latin America, 18 per cent in Africa, and 51 per cent water pollution varies from month to month due to the in Asia where faecal coliform levels increased to a influence of different monthly river basin conditions severe level, or were at a severe level in 1990 and had on a river’s capacity to dilute wastewater, on the die- worsened by 2010. These can be considered hot spot off rate of bacteria in streams, and on the pollution areas. Above, an alternative definition for “hot spot washed-off from land surfaces. Therefore, it is also areas” was used, namely, river stretches having severe important to estimate the month-to-month variation pathogen pollution for six months or more per year. of faecal coliform bacteria throughout the year. Table It turned out that there is a considerable overlap in 3.3 provides estimates of the length of river stretches the river stretches that are hot spots according to both affected by pathogen pollution taking into account the sets of criteria (Table 3.4). Particular attention should month-to-month variation of river pollution. Around be paid to these areas in further efforts at monitoring 261,000 to 327,000 km of Latin America’s rivers, or and investigating pathogen river pollution. 1Results are presented for an average February over a three year period (2008–2010) to avoid presenting anomalous results caused by unusual weather conditions in a particular month and year. 2Here and elsewhere in the modelling analysis the water quality conditions during the three-year period 2008 to 2010 were examined rather than only those of 2010. A three year period is used to filter out unusual monthly water flow conditions that might lead to unusually high or low levels of in-stream concentrations 18 of pollutants. The focus of this assessment was to determine the overall average state of water quality in rivers rather than the worst or best conditions.

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Table 3.2: Overview of data availability and statistical values for faecal coliform bacteria in the time period 2000–2010. Data source: GEMStat. SD = Standard deviation. Units: [cfu/100 ml]

No. of stations/ No. of Continent Median 10th percentile th90 percentile SD 10,000 km² measurements

Latin America 0.027 1,725 135 0 17,410 367,514

Africa 0.001 215 1,500 93 46,000 112,006

Asia 0.036 4,131 140 3 4,000 135,742

Figure 3.2: Statistical distributions of all GEMStat faecal coliform data in Latin America, Africa and Asia for the period 2000– 2010. Box-and-whisker plots (left) and cumulative frequencies (right). The upper and lower boundaries of the boxes in the box-and-whisker plots indicate the 25th to 75th percentile and the line in between these boundaries the median (50th percentile).

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Table 3.3: Length and percentage of river stretches (km) within various pathogen pollution classes. The minimum and maximum monthly stretches within the period of 2008 to 2010 are indicated.a

Water pollution Faecal coliform concentration Latin America Africa Asia class (cfu/100 ml) (min, max) (min, max) (min, max) 722,000–785,000 965,000–1,122,000 553,000–886,000 Low pollution x ≤ 200 60–65% 63–74% 35–56% Moderate 157,000–160,000 203,000–216,000 203,000–236,000 200 < x ≤ 1,000 pollution ~13% 13–14% 13–15% 261,000–327,000 200,000–343,000 493,000–793,000 Severe pollution x > 1,000 22–27% 13–23% 31–50% aMinimum and maximum estimates are the lowest and highest monthly estimates per continent in the 36-month period from 2008 to 2010. These are the ranges which correspond to the cases in which severe pollution is at a minimum or maximum on a continental basis.

Figure 3.3: Estimated in-stream concentrations of faecal coliform bacteria (FC) for Latin America, Africa and Asia for February 2008–2010. Bar charts show minimum and maximum monthly estimates of river stretches in the severe pollution class per continent in the 36-month period from 2008–2010, corresponding to data in Table 3.3.

Figure 3.4: Frequency (months/year) in which “severe pollution” levels of faecal coliform bacteria occur in different river stretches over the period from 2008–2010.

3“Increasing trend of particular concern” in this report means a pollution level that increased into the severe pollution category in 2008-2010, or was already in the severe pollution category in 1990–1992 and further increased in concentration by 2008–2010. 20

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Figure 3.5: Trend in faecal coliform bacteria levels in rivers between 1990–1992 and 2008–2010. River stretches marked with orange or red have increasing concentrations between these two periods. River stretches marked red have an “increasing trend of particular concern”3.

Table 3.4: Hot spot areas of faecal coliform pollution appearing in both Figure 3.4 and Figure 3.5.

• Central America • Some river stretches in Southern Africa • West coast of Latin America • Middle East • Upland river basin on Argentina border • Ganges river basin • East coast of Latin America • Some river stretches in Southern India • Northwest Africa • Many river stretches in East Asia • Nile river basin

Box 3.1: Estimating the rural population coming in contact with severe pathogen pollution The following method was used to estimate the size of the rural population coming in contact with surface water severely polluted with faecal coliform bacteria (> 1000 cfu/100 ml). First, data on the percentage of rural population using surface waters for bathing, washing or as main water source were gathered from various case studies in developing countries (e.g. Brazil, China, Ghana, and Nigeria). Secondly, national data on the percentage of rural population using surface water as drinking water were compiled from the WHO/ UNICEF Joint Monitoring Programme (JMP). The JMP data were used as a proxy of the percentage of rural people using surface water and as a lower limit of estimates for each country since the JMP data were found to be usually smaller than literature data from these countries. To make an upper limit for each country, the JMP estimate for a particular country was multiplied by a factor of 1.94. The factor 1.94 is the median ratio between literature values in various case studies from different countries and the JMP national value of the country where the case studies took place. In this way, lower and upper estimates were derived of the percentages of rural population in each country that regularly comes in contact with surface waters. Next, the subset of rural people was estimated who not only use surface water but also may come into contact with polluted water. Using the gridded population data base from HYDE (version 3.1; Klein Goldewijk, 2005; Klein Goldewijk et al., 2010) and UNEP (2015a) the rural population living in proximity of river stretches in the “severe pollution” category of faecal coliform bacteriaa (i.e. within one grid cell, or approximately 10 km, of the respective river stretches) was estimated. For each country, the number of rural people living in proximity of the severe pollution was multiplied by the upper and lower estimates of the percentage of rural people using surface waters. As a result the estimates in Table 3.5 were obtained. This procedure may lead to an overestimate of the people exposed to pathogen pollution because people obviously avoid, if possible, surface waters that are grossly polluted. On the other hand, the number of people exposed may be underestimated because urban populations are not taken into account, and because the percentage of people using surface waters near rivers is likely to be proportionately higher than the national average percentage data coming from the JMP data base. aFor these estimates the river stretches in the severe pollution category for faecal coliform bacteria in the median month (on a continental basis) over the 36-month period during 2008-2010 were used.

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3.2.3 People at risk of pathogen river pollution at least up to hundreds of millions of people may be A very important question in assessing the world water at a health risk because of their contact with polluted quality situation is the number of people at health risk surface waters. through contact with surface waters. Unfortunately, no While both men and women use surface waters for authoritative global estimates exist. Many published bathing, women are at particular risk because of studies (See Appendix B) estimate that 5 per cent or their frequent usage of water from rivers and lakes more of rural inhabitants in many developing countries for cleaning clothes and collecting water for cooking regularly come into contact with surface waters. It is and drinking in the household (Adeoye et al., 2013; expected that the exposure of the rural population to Barbir and Prats-Ferret, 2011; Gazzinelli et al., 1998; contaminated surface water through bathing, clothes Kabonesa and Happy, 2003; Lindskog and Lundquvist, washing, etc. will be much larger than the exposure of 1989; Manyanhaire and Kamuzungu, 2009; Sow et the urban population because urban populations tend al., 2011; Thompson et al., 2003). Children are also at to be more often serviced with public water supply particular risk because of their play activities in local and tend to have less access to surface waters. surface waters and also because they often have the The number of rural people coming in contact with task of collecting water for the household (Adeoye et polluted surface waters was estimated as described in al., 2013; Aiga et al., 2004; Choy et al., 2014; Engel et Box 3.1. For Latin America, the number of people is al., 2005; Gazzinelli et al., 1998; Kabonesa and Happy, estimated to be approximately 8 to 25 million people, 2003; Lindskog and Lundquvist, 1989; Sow et al., 2011; for Africa around 32 to 164 million, and for Asia around Thompson et al., 2003). 31 to 134 million people (Table 3.5). The ranges reflect Using polluted water for irrigation also poses a health the uncertainties of these first estimates, which are risk to both the farmers who come in direct contact based on literature and the JMP database. Despite the with the water and the consumers of fruits and uncertainties, the message of these estimates is that vegetables irrigated with polluted water (FAO, 1997).

Table 3.5: Estimated number of people (in millions) living in rural areas coming in contact with surface waters that were severely polluted. Estimates for period 2008 to 2010.

Latin America Africa Asia (min, max) (min, max) (min, max) 8.1–24.8 31.7–164.3 30.6–133.7

3.2.4 Sources of faecal coliform bacteria Most of the faecal coliform pollution in Latin America Many factors influence the level of faecal coliform comes from sewered domestic wastes (81 per cent) bacteria in rivers. One is the capacity of the river followed by non-sewered domestic sources. Collection to dilute wastewater loadings of bacteria; another of domestic sewage and its untreated delivery to is the die-off rate of these bacteria as it is affected rivers has contributed to bacterial pollution in rivers. by temperature, sunlight and their settling rates. Rivers flowing through densely-populated urban and These factors are taken into account as described in industrial areas are more likely to be contaminated by Appendix B. faecal coliform bacteria (see Figure 3.8) and tend to fall into the “severe pollution” category for faecal coliform A very important factor, and one that society can bacteria. Other sources of faecal coliform loadings are influence considerably, are wastewater loadings into urban surface runoff and wastewater discharges from surface waters. Several sources of loadings are taken the manufacturing sector. into account as shown in Table 3.6. These loadings depend on the waste produced per person, the type For Africa, the majority of faecal coliform bacteria come of sanitation, the degree to which sanitation systems from non-sewered domestic sources (56 per cent) are connected to sewers, and the level to which followed by sewered domestic sources (41 per cent) sewage is treated. Controlling levels of faecal coliform from scattered settlements. Sub-Saharan countries bacteria loadings at the source is the key to providing have the lowest levels of sanitation coverage. In this microbiologically safe drinking water and surface region, 644 million people had no access to an improved waters (see Chapter 5). sanitation facility in 2012 (WHO/UNICEF, 2014a).

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In Asia, about half the faecal coliform bacteria comes As noted earlier, the levels of faecal coliform bacteria from sewered domestic waste. The other half comes in rivers have been estimated to increase over the last from non-sewered domestic waste sources from two decades because of increases in loading. On the scattered settlements. Only about one-third of all continental average basis, from 1990 to 2010 loadings wastewater in Asia is treated; the lowest treatment have increased by 64 per cent in Latin America, by 97 rates are in South Asia (about 7 per cent) and Southeast per cent in Africa and by 86 per cent in Asia (Figure Asia (about 14 per cent). According to the Report of 3.7). Faecal coliform loadings increased mainly the WHO/UNICEF Joint Monitoring Programme on because of the large increase of domestic wastes, Progress on Drinking Water and Sanitation (WHO/ both sewered and non-sewered. Main driving forces UNICEF, 2014a), more than 1 billion people have no of these increases have been the growth of population access to an improved sanitation facility in Southern and growing sewer connections without treatment of Asia, including 792 million people in India. Due to wastewater. It is likely that loadings of faecal coliform the high population density together with a low-level bacteria to rivers would have been lower if the new coverage of improved sanitation and treatment, faecal sewer systems had not been built (See Box 3.2). coliform loadings are considerable and cause severe pollution in many rivers in Asia.

Box 3.2: Faecal coliform loadings to rivers are higher because of the lack of wastewater treatment. As noted in the text, pathogen pollution has increased over large stretches of rivers over the past decades. A large fraction of the increase is due to the expansion of sewer systems that discharge wastewater untreated into surface waters. If the sewer systems had not been built, it is likely that the loadings of faecal coliform bacteria to Africa’s rivers would have been around 23 per cent lower than they are now (See Figure 3.6 below). This is because the new sewers deliver human wastes to rivers that would otherwise have remained (unsafely) on the land. On one hand, by taking the wastewater away from populated areas, the sewers have reduced the health risk posed by unsafe sanitation practices on land. On the other hand, by dumping sewage untreated into surface waters, they have transferred the health risk from the land to surface waters. The solution, however, is not to build fewer sewers, but to treat the wastewater they collect. Figure 3.6 shows faecal coliform loadings for Latin America, Africa and Asia in 2010 according to two sets of assumptions. The left bar of each continent is the best estimate for 2010. This estimate takes into account increasing rates of connections to sewer systems (as described in Appendix B). The right bar is an estimate assuming that connection rates to sewers did not increase after 1990. The difference between this estimate and the best estimate shows the impact of expanding sewer systems on faecal coliform loadings.

Figure 3.6: Faecal coliform bacteria loadings for Latin America, Africa and Asia for two sets of assumptions: the “best estimate 2010” and “without expansion of sewers”.

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Table 3.6: Categories of faecal coliform bacteria loadings accounted for in estimates of in-stream concentrations.

• Domestic sewered (point sources) • Domestic non-sewered – hanging latrines (point sources); domestic septic tanks, pit toilets, open defecation (diffuse sources) • Manufacturing (point sources) • Urban surface runoff (diffuse sources) • Agriculture – animal wastes (diffuse sources)

Figure 3.7: Faecal coliform bacteria loadings for Latin America, Africa and Asia for 1990 and 2010.

Figure 3.8: Distribution of faecal coliform loadings according to source for 2010. Units: percentage.

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3.3 Organic pollution and the threat to the inland fishery and food security

3.3.1 What is organic pollution? 3.3.2 The importance of inland fisheries to food The health of fish and aquatic fauna is threatened security by many changes to the natural state of water Inland fisheries represent an invaluable and often bodies, including the destruction of their habitat, irreplaceable contribution to food security for hundreds contamination with trace toxic substances, and of millions of people in poor, rural communities “organic pollution”. Here the focus is on “organic around the world (FAO, 2003; World Bank et al., 2010). pollution”4, a common term used to describe the set The reported global inland fisheries harvest in 2012 of processes associated with depletion of dissolved was 11.6 million tonnes (FAO, 2014), although these oxygen in a water body (e.g. EEA, 2015; Lobo et al., harvest figures are widely acknowledged to be grossly 2015; Noel & Rajan, 2015; Gao et al., 2013; Vidal et al., underestimated in many countries (FAO, 2012). 2013; Haury et al., 2006; FAO, 1996). Organic pollution Globally, fish from inland waters is the sixth most occurs when an excess of easily biodegradable important supplier of animal protein (Welcomme, matter enters surface waters. The decomposition of 2010). Locally, the inland fish catch can be a much this matter by bacteria and other microorganisms more significant source, especially for populations consumes oxygen and depletes dissolved oxygen from living near rivers and lakes and in land-locked countries the water column. The depletion of dissolved oxygen (Welcomme, 2010). For example, the catch of inland has a very negative effect on aquatic fauna, especially fish accounts for 44 per cent of the animal protein fish and benthic invertebrates, which rely on this produced in Malawi, 64 per cent in Bangladesh and oxygen for their survival and functioning. Cambodia, and 66 per cent in Uganda (2007 figures There are many different causes of organic pollution. from Welcomme, 2010). The main causes in rivers near heavily populated and China, Bangladesh, India, and Myanmar recorded the industrialised areas are discharges of domestic and highest inland catch both in Asia and the world with industrial wastewater which typically contain large over 1 million tonnes each in 2010, while Cambodia, quantities of biodegradable or oxidisable substances. Myanmar and Uganda had the highest consumption Another cause, particularly where rivers are per person with 27, 20, and 12 kg/capita for 2010, impounded, is eutrophication. In this case, large respectively (Welcomme, 2011). loads of nutrients into the river from domestic and These fisheries harvest hundreds of aquatic species agricultural sources stimulate the growth of algae in from almost all freshwater ecosystems (Welcomme, the slow moving reaches of rivers behind dams. When 2011). They are characteristically informal in nature, the algae die off they are decomposed by bacteria require no or low entrance fees, minimal start-up and other microorganisms which deplete the oxygen costs and equipment, and need only basic skill levels resources of the river. Organic pollution is also caused to participate. Thus, inland capture fisheries are an by the wash off of animal wastes into rivers, urban important source of livelihoods and employment in runoff, and other sources. developing countries. For the period of 2010 to 2012, We begin this subchapter with a discussion of inland FAO (2014) estimated that inland fisheries provided fisheries because they are particularly threatened by employment for 21 million fishers. Inland fisheries also organic pollution. provided 38.5 million jobs in post-catch processing and other related activities (World Bank et al 2010). Almost all of these jobs were in small scale fisheries, occupied by mostly low-income people, with over half of the total workforce being women (World Bank et al., 2010).

4Should not be confused with problem of “persistent organic pollutants” (POP) which are “chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment”(UNEP, 2015b). 25

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[kg/cap/yr]

Figure 3.9: National dietary intake of inland fisheries yields (kg/capita/2010). Data Source: FishstatJ (FAO, 2014), country population data (World Bank)

Figure 3.10: National inland fisheries catch trend between the time periods 1990–1999 and 2000–2010. Data Source: FishstatJ (FAO, 2014).

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Figure 3.11: Percentage of river stretches in each country with “increasing trend of BOD of particular concern” meaning that in these stretches the pollution level increased into the severe pollution category in 2008–2010, or that they were already in the severe pollution category in 1990–1992 and further increased in concentration by 2008–2010 (cf. Figure 3.15).

Catches are either utilised for direct consumption, Another important factor relevant to inland fisheries used in bartering agreements, or sold at local and food security is the trend in inland fish catches markets providing additional access and availability (Figure 3.10). Global reported inland fisheries catches to community members not directly involved in the have been increasing steadily since 1950 at a rate of fishery (World Bank, 2010). The large, dispersed scale 2.9 per cent per year (Welcomme, 2011). The country that inland fisheries typically operate on also helps trends of inland fish catches were calculated in order to maintain supply stability and avoid disruptions on to determine if catches were increasing or decreasing a local scale, as can post-harvest processing such as since 1990. Decreasing catches in a country dependent drying and salting or refrigeration of excess product in on fish consumption may indicate an increasing risk more developed areas. to food security. Of course, they may also reflect a As inland fisheries provide an essential source of population becoming more wealthy and preferring protein and micronutrients for millions of people not to consume inland fish. Increasing catches may across the developing world, it is of interest where indicate somewhat higher food security. On the other they have the greatest relevance to food security. One hand, if catches increase beyond the sustainable levels indicator is the national dietary intake of freshwater for the fishery, then fish populations may strongly catches per capita, which provides an approximation depleted and this would pose an even greater risk to of the level of consumption as well as the potential food security. In general, it is difficult to interpret the availability of fishery resources for individuals (Figure meaning of a decreasing or increasing catch, and it 3.9). This indicator assumes all aquatic products from should be used only as a very preliminary indicator of inland fisheries are consumed in-country, which is true the status of a fishery. for most situations (FAO, 2003). It must also be noted The national catch trend for developing countries that the consumption of inland fisheries resources indicates that 62 per cent of the countries considered are generally higher in rural regions, particularly have increasing catches while 38 per cent reported in communities residing adjacent to lake and river decreasing ones. An overview of the results shows networks, than in major city settlements. countries with a decreasing trend in Central Asia and Considering all developing countries with reported the Middle East, Central America, the Caribbean and inland fisheries catch data, 36 per cent were identified some Northern countries of South America as well as as being at a “higher vulnerability”, with most of these in various countries throughout Africa (Figure 3.10). countries located in Central and West Africa and Southeast Asia (Box 3.3).

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Box 3.3: Proposed methodology for computing indicators relevant to the status of the inland fishery One of the main objectives of this pre-study towards a World Water Quality Assessment was to develop a concept for the identification of regions where inland fisheries are vulnerable to water quality deterioration, and where food security may be reduced. First, preliminary indicators of inland fisheries (Section 3.3.2) and water quality (Box 3.3) are developed. Secondly, these indicators are linked to evaluate how and where water quality degradation has an impact on the capacity of inland fisheries and their relation to food security on a global scale (Figure 3.12). As an example, a preliminary comparison is made in Section 3.3.3 of inland fishery indicators (national dietary intake and national fish catch trends) and a water quality indicator (location of “increasing BOD trends of particular concern”). For preliminary estimates of inland fishery indicators, existing data from international databases such as FAO (Fishery and Aquaculture Global Statistics – FishstatJ), and The World Bank (country population data), were used. The calculations considered only freshwater fish with aquaculture data excluded. To calculate the indicator “national dietary intake of inland fisheries” (kg/capita/2010), the total reported inland fisheries catch per country was divided by country population. The data were then categorised into “higher” or “lower” intake based on the calculation of the 75th percentile of countries reporting inland fisheries yields. In that regard, countries were classified as being either at a “higher intake” level with ≥ 1.86 kg/capita/yr or a “lower intake” with < 1.86 kg/capita/yr. The indicator “national inland fisheries catch trend” was calculated by comparing average decadal yields from 1990–1999 with 2000–2010. Decadal averages were used because of large year-to-year fluctuations. This is a very approximate indicator of the possible status of inland fishery resources because it does not indicate the specific reasons for an increasing or decreasing trend. Furthermore, additional factors will be considered including the development level of a country and the occurrence of over-fishing. The data used for these indicators were only available on a country scale in the FAO Fishstat database. However, there is a need to downscale the indicators to the river basin or lower scale so that they can be related to water quality and other river conditions. This will allow for a more detailed investigation of the threat of increasing water pollution to fish populations of particular importance to food security.

Inland fisheries relevance Water quality relevance

Indicators: Indicators: • National dietary intake of inland captured • Level of concern of water quality parameters fishery yields • Trends of BOD instream concentration • National inland fiesheries catch trends

Rating: Rating: • “higher” or “lower” intake • percentage of exceedances • “increasing” or “decreasing” trend • “increasing” or “decreasing” trend

Linking inland fisheries and water quality relevance

Inland fisheries assessment on a global scale

Figure 3.12: Preliminary scheme for assessing the status of inland fisheries with regard to water quality degradation.

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3.3.3 What is the level of organic pollution? Together, these results point to an overall picture As already noted, organic pollution is of particular of concern regarding water quality and the inland concern because it threatens the functioning of inland fisheries of Latin America, Africa, and Asia. fisheries and aquatic ecosystems in general. Here, Modelling analysis results from GEMStat concerning water quality levels After the examination of results for five water quality in Latin America, Africa, and Asia and how they relate parameters with the help of the GEMStat database, the to the health of the inland fishery are examined first. spatial and temporal trends of one of these indicators, Then a closer look is taken at the spatial and temporal BOD, was looked at more closely. BOD is often taken dimensions of one of these indicators, biochemical as the principle indicator of organic pollution (Box oxygen demand (BOD). 3.4). As for faecal coliform bacteria in Section 3.2.2, GEMStat analysis the WorldQual model is used to compute the monthly Certain water quality parameters related to organic concentration of BOD in Latin America, Africa, and pollution are particularly relevant to the health of the Asia from 1990 to 2010. inland fishery (see Box 3.4). These parameters are: Based on water quality guidelines from 11 different dissolved oxygen, biochemical oxygen demand (BOD), countries (Appendix B), BOD results were clustered ammonia, chloride, and pH. The second-to-last column into the three water quality classes shown in Table of Table 3.7 presents levels of concern for these five 3.8. Figure 3.13 shows an example of average monthly key parameters, with particular consideration given levels of BOD for February 2008-2010 clustered into to the tolerance levels of fish. Values outside these three classes. Severely polluted river stretches include limits indicate a high risk to the reproduction, growth, northern and eastern parts of Latin America, northern respiration, and feeding of fish. Because of the very and eastern Africa as well as many parts of Asia. wide variety of fish in Latin America, Africa, and Asia; Figure 3.13 shows the modelled BOD in-stream these “levels of concern”5 are only a very general concentrations on a monthly average basis for guide to their tolerance limits. February 2008–2010. However, it is known that Table 3.7 presents the percentage of stations where levels of BOD vary from month to month because of the five key parameters are at levels of concern. Since changing dilution capacity, temperature-related BOD there is a wide variation in the spatial and temporal decay, and runoff of pollutants. Figure 3.14 shows coverage of the different parameters, only general the frequency of months each year in which severe conclusions can be drawn from this analysis: BOD pollution levels occur from 2008 to 2010. As for • In Latin America, at least 10 per cent of the faecal coliform bacteria, it is assumed that the more measurements for dissolved oxygen, ammonia, frequently high BOD levels occur throughout the year and pH exceed levels of concern for these the greater the impacts of high BOD levels. Therefore, parameters. river stretches with severe pollution during six months or more each year are taken as an indication of hot • In Africa, at least 20 per cent of the measurements spot areas. According to this definition, hot spots for dissolved oxygen, BOD, and chloride exceed appear in Central America, eastern South America, these levels. Northeast Africa, South and East Asia. • In Asia, at least 10 per cent of the measurements Table 3.9 shows the length of river stretches with for dissolved oxygen6, BOD7, ammonia, chloride, different levels of BOD pollution, taking into account and pH exceed these levels. the month-to-month variation of BOD. A range of • In Table 3.7, ranges are given for the level of 60,000 to 117,000 km of Latin America’s rivers, concern for BOD. For the more stringent level, equivalent to about one-tenth of its total river 10 per cent of the measured BOD data in Latin stretches, are in the severe pollution class. In Africa, America, 40 per cent in Africa, and 15 per cent in 132,000 to 234,000 km, or around one-sixth of its river Asia are at a level of concern for BOD. stretches, are in the severe river pollution class, and in In conclusion, at least 10 percent of measurements Asia 168,000 to 268,000 km, or also about one-sixth of from all three continents show levels of concern for all of its river stretches. at least three out of five water quality parameters Figure 3.15 shows the trend in BOD river of particular importance to the health of fisheries. concentrations between the early 1990s and late

5“Level of concern” in this report is used to mean the pollutant concentration above (or below) which significant negative impacts occur. In this report, these concentrations are derived from water quality standards from official sources such as government departments or UN agencies. 6Considering an intermediate value of the range in Table 3.7. 7Considering an intermediate value of the range in Table 3.7. 29

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2000s. BOD concentrations have increased in 54 per Preliminary comparison of inland fishery indicators cent of the river stretches in Latin America, 62 per cent with a BOD indicator of the river stretches in Africa, and 71 per cent of the The BOD hot spots (“increasing areas of particular river stretches in Asia. In total, 63 per cent of the river concern”) shown in Figure 3.15 are also of importance stretches on these three continents have an increased to inland fisheries because these areas have both a BOD concentration. high and an increasing level of BOD. High levels of BOD River stretches marked with red in Figure 3.15 have an often coincide with low levels of dissolved oxygen and “increasing trend of particular concern”. In these river threaten the local survival of fish and other aquatic stretches, the concentration of BOD increased into fauna (Box 3.4). Figure 3.11 summarizes these data on the severe pollution category in 2008-2010, or it was a country level so that they can be compared to the already in the severe pollution category in 1990-1992 earlier maps of country-scale consumption of fish and and further increased in concentration by 2008-2010. trends in fish catch (Figure 3.9 and Figure 3.10). These river stretches amount to 6 per cent of the total A comparison of the three maps indicates two subsets lengths of rivers in Latin America, 12 per cent in Africa of countries whose inland fisheries may be particularly and 13 per cent in Asia and could also be considered vulnerable to increasing organic pollution: hot spot areas. The overlap of hot spot areas according • One subset of 10 countries8 has both a higher to this definition and the definition used earlier (Figure consumption of fish from the inland fishery 3.14 and Figure 3.15) is shown in Table 3.10. River and increasing organic pollution (>10 per cent basins listed in this table could be considered as BOD as indicated by Figure 3.11) (with increasing or hot spot areas with high confidence since they appear decreasing catch). as hot spots according to two different definitions. • A second subset of 16 countries9 has decreasing These areas should be paid particular attention in catch together with increasing organic pollution further monitoring and investigation efforts of organic (>10 per cent). river pollution. The combination of indicators may indicate an To sum up the modelling analysis of BOD, results increasing risk to the inland fisheries of these show that the lengths of river stretches with high BOD countries. At a minimum, it is worthwhile for these levels on all three continents are in the hundreds of countries to be vigilant against increasing water thousands of kilometres, and that most stretches of pollution endangering their inland fisheries and the rivers also have increasing concentrations. food security and livelihoods they provide.

Box 3.4: Water quality parameters of concern to health of inland fisheries Dissolved oxygen (DO) is a fundamental water quality parameter (UNEP, 2008) related to the sustainability of freshwater fisheries and aquatic ecosystems integrity. A minimum level of dissolved oxygen is needed to prevent lethal and sub-lethal (physiological and behavioural) effects on fish and other higher organisms (CCME, 1999). While dissolved oxygen is depleted by the decomposition of organic matter and may be completely consumed under excessive organic loads, it also can also show high supersaturation caused by the photosynthesis of algae and other aquatic flora under eutrophic conditions. The solubility of oxygen in water strictly depends on the temperature and decreases with increasing temperatures. Both parameters are ecological key factors which control the occurrence and geographical spread of species. For this reason, two levels of concern for fish communities adapted to cold or warm water are given in Table 3.7. Biochemical oxygen demand (BOD) is a key indicator of organic pollution (EEA, 2015) and indicates high levels of biodegradable organic matter in the water. High BOD loads usually cause significant depletions of dissolved oxygen and deleterious effects on fish and other biota. One example is the Tietê River in Brazil, presented as a case study in Chapter 4. The Tietê picks up large loads of organic wastes from

8Chad, Kenya, Mali, Nigeria, Senegal, Vietnam, Sudan, Turkmenistan, Uganda, Egypt. 9Chad, Cuba, Dominican Republic, Ecuador, El Salvador, Haiti, Iran, Israel, Jamaica, Kenya, North Korea, Mexico, Pakistan, Somalia, Turkmenistan, Uzbekistan 30

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domestic and industrial sources as it flows through the city of São Paulo. These loads reduce dissolved oxygen levels in the river to levels as low as 2 mg/l and the low level of dissolved oxygen together with the presence of other pollutants has drastically reduced the number and diversity of fish species in the river around the city. It should be noted that high BOD is not always correlated with low dissolved oxygen and threats to fish in the vicinity of wastewater discharges. Dependent on river conditions, dissolved oxygen could be at a satisfactory level at the entry point of BOD discharged into a river because of the time dependent biochemical degradation of the organic matter. Furthermore, under high nutrient loading and eutrophic conditions the biomass of algae or macrophytes may significantly contribute to the BOD loading. However, high levels of BOD in aquatic ecosystems are typically associated with significant oxygen depletion and therefore, the German national water quality guidelines indicate that low oxygen levels and periodic fish kills may be expected at BOD concentrations greater than 8 mg/l (LAWA, 1998). Another key indicator of organic pollution (EEA, 2015) and of particular concern to fish health ammoniais . 4+ Ammonia exists in two forms in water – un-ionized (NH3) and ionized (NH ). Ammonia is taken up as a nutrient by aquatic plants and is typically oxidized to nitrate through the process of “nitrification” which consumes oxygen. In higher concentrations, ammonia is of concern for two major reasons. First, it is

toxic to fish, particularly in its un-ionized form (NH3). The pH of the river or lake plays an important role here, because the higher the pH the higher the percentage of the total ammonia which is dissociated into its toxic un-ionized form. Secondly, the respiration due to nitrification may lower the oxygen levels of running and stagnant waters below ecological thresholds. Chloride is another parameter of concern to the status of the fishery. High chloride concentrations can impair the “osmoregulation” (internal regulation of water and salts) of fish and other organisms and impair their survival, growth, and/or reproduction (CCME, 1999). Chloride can originate from many sources, including those associated with organic pollution such as domestic wastewater. Hence it is sometimes present in high concentrations when BOD levels are also high. But chloride in rivers and lakes also has other sources not usually associated with organic pollution such as road salts used in developed countries for de-icing roads, drainage flows coming from irrigated farmland, and sea spray. The pH of a river or lake is also of concern to the inland fishery. Above we described that at high pH ammonia is dissociated in its toxic un-ionized form. Water with low pH interferes with the ability of fish to take up oxygen, changes the acid-base regulation at the gills, and has other deleterious effects on the physiology of fish (Matthews, 1998). High pH can reduce the ability of fish to excrete ammonia or regulate their internal ion balance (Carpenter et al., 2012). Low pH in lakes and smaller streams is often not associated with organic pollution, but with another water quality problem, namely acidification. Acidification is caused by “acid deposition”, i.e. the atmospheric deposition of acidifying sulphur and nitrogen compounds, into a lake (Heard et al., 2014; Rubin et al., 1992). Acid deposition can stimulate the release of aluminium and other heavy metals from soils into lakes where they pose an additional threat to the health of fish. Exceptionally low or high pH in rivers can result from the discharge of domestic or industrial wastewater containing acidic or alkaline compounds.

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Table 3.7: “Levels of concern” of water quality parameters with respect to inland fisheries and percentage of measurements exceeding the levels of concern in Latin America, Africa and Asia in the time period 2000-2010. Data from GEMStat. Water quality standards are listed in Appendix B.

Dissolved Oxygen (mg/l) No. of stations/ No. of Median Percentage of data exceeding Continent Levels of concern 10,000 km² measurements (all data) the levels of concern Latin America 0.145 5,200 6.3 x < 5a / x < 7b 17.1%a / 51.9%b Africa 0.002 289 6.9 x < 5a / x < 7b 23.8%a / 40.8%b Asia 0.052 7,380 7.0 x < 5a / x < 7b 7.1%a / 26.3 %b BOD (mg/l) No. of No. of Median Percentage of data exceeding Continent Levels of concern stations/10,000 km² measurements (all data) the levels of concern Latin America 0.053 2,957 2.0 4 < x < 8 / x > 8 4.8% / 4.7% Africa 0.001 236 3.3 4 < x < 8 / x > 8 23.3% / 21.6% Asia 0.058 5,329 1.7 4 < x < 8 / x > 8 14.7% / 4.8% Ammonia (mg/l) No. of No. of Median Percentage of data exceeding Continent Levels of concern stations/10,000 km² measurements (all data) the levels of concern Latin America 0.216 2,664 0.08 x > 0.3 12.4% Africa 0.012 1,581 0.04 x > 0.3 6.4% Asia 0.045 3,045 0.04 x > 0.3 15.7% Chloride (mg/l) No. of No. of Median Percentage of data exceeding Continent Levels of concern stations/10,000 km² measurements (all data) the levels of concern Latin America 0.115 3,541 5.3 x > 120 0.25% Africa 0.014 1,482 51.7 x > 120 29.0% Asia 0.042 2,735 17.0 x > 120 12.9% pH (-) No. of No. of Median Percentage of data exceeding Continent Levels of concern stations/10,000 km² measurements (all data) the levels of concern Latin America 0.155 5,449 7.2 x ≤ 6.5 / x ≥ 8.5b 20.0% / 1.7% Africa 0.014 1,639 8.1 x ≤ 6.5 / x ≥ 8.5b 0.1% / 13.8% Asia 0.052 7,615 7.5 x ≤ 6.5 / x ≥ 8.5b 4.4% / 5.6%

a Criteria for warm water biota; measurements with temperature > 20°C and oxygen < 5 mg/l O2 b Criteria for cold water biota; measurements with temperature < 20°C and oxygen < 7 mg/l O2

Table 3.8: Classes of organic water pollution according to river concentrations of BOD used in this report. Concentration is expressed in mg/l and based on water quality standards of 11 countries listed in Appendix B.

Water pollution class BOD concentration (mg/l) Description* Indicates river stretches with low organic load and Low pollution x ≤ 4 usually sufficient oxygen supply and high species diversity. River stretches with moderate organic load but Moderate pollution 4 < x ≤ 8 possibly critical oxygen conditions; suspended discharges occur but have no major effect on biota. River stretches where depletion of dissolved oxygen Severe pollution x > 8 can be extreme, likely resulting in fish kills. *derived from the German national water quality guidelines

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Table 3.9: Length and percentage of river stretches (km) within various organic pollution classes. The minimum and maximum monthly stretches in the period of 2008 to 2010 are shown.

BOD concentration Latin America Africa Asia Water pollution class (mg/l) (min, max) (min, max) (min, max)

959,000–1,038,000 1,238,000–1,349,000 1,237,000–1,342,000 Low pollution x ≤ 4 86–91% 81–89% 78–85%

33,100–52,000 44,000–53,000 72,000–77,000 Moderate pollution 4 < x ≤ 8 3–4% 3–4% 4–5%

60,000–117,000 132,000–234,000 168,000–268,000 Severe pollution x > 8 6–10% 7–15% 11–17%

Figure 3.13: Estimated in-stream concentrations of biochemical oxygen demand (BOD) for Latin America, Africa, and Asia for February 2008–2010. Bar charts show minimum and maximum monthly estimates of river stretches in the severe pollution class per continent in the 36-month period from 2008–2010, corresponding to data in Table 3.9.

To sum up, the GEMStat analysis showed that 10 per of thousands of river kilometres were in the severe cent or more of all measurements in Latin America, pollution class, with the majority of streams having Africa, and Asia had levels of key water quality increasing concentration. One overarching conclusion parameters that are of concern to the health of is that countries who rely on their inland fisheries as inland fisheries. The modelling analysis of BOD on an important food source should be vigilant about the these continents confirmed these results, showing increasing level of organic pollution. that 6–17 per cent of the river stretches or hundreds

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Figure 3.14: Frequency (months/year) in which “severe pollution” levels of biochemical oxygen demand occur in different river stretches over the period 2008–2010.

Figure 3.15: Trend in BOD concentrations in rivers between 1990–1992 and 2008–2010. River stretches marked with orange or red have increasing concentrations between these two periods. River stretches marked with red have an “increasing trend of particular concern” meaning that in these stretches the pollution level increased into the severe pollution category in 2008– 2010, or that they were already in the severe pollution category in 1990–1992 and further increased in concentration by 2008–2010.

Table 3.10: Selected hot spot areas of organic pollution appearing in both Figure 3.14 and Figure 3.15.

• Central America • Some river stretches in Northwest Africa • Vaal river basin • Limpopo river basin • River stretches in the Middle East • Indus river basin • Ganges river basin • Some river stretches in Southern India • Haihe, Huaihe and Yellow river basins

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3.3.4 Sources of organic pollution concentrations and to identify the main contributing Several sources of BOD loading are taken into account sectors. as shown in Table 3.11. These loadings depend on the Figure 3.17 shows the main sources of organic waste loadings per person, the type of sanitation, the pollution according to the three regions for the year degree to which sanitation systems are connected to 2010. In Latin America about 60 per cent of the total sewers and wastewater is treated, and the loadings loadings originated from domestic sewered sources washed-off from agricultural land and urban surfaces. while only 11 per cent can be allocated to the domestic Controlling levels of organic loadings at the source non-sewered sector. Wastewater from manufacturing is the key to reducing or preventing anthropogenic industries accounts for 28 per cent of the loadings, wastewater intakes into surface waters (see Chapter 5). while the contribution from the agricultural sector and Estimates of loadings of organic pollution ona urban surface runoff to BOD loadings is about 2 per continental basis for the years 1990 and 2010 are cent. High loadings from point sources, like sewered shown in the bar charts in Figure 3.16. As noted domestic wastewater and manufacturing wastewater, earlier, the levels of organic pollution in rivers have indicate that wastewater is probably collected, but not been estimated to increase over the last two decades sufficiently treated. because of increases in loadings of BOD. On the The main sources of BOD loadings in Africa are non- continental average basis, loadings have increased sewered (49 per cent) and sewered (36 per cent) by 30 per cent in Latin America, 65 per cent in Africa, domestic sources from urban and rural populations. and 95 per cent in Asia. The continental average data, In total 85 per cent of loadings are from domestic however, mask important differences between sub- sources (Figure 3.17). Approximately 13 per cent of regions which may differ depending on the rate of BOD loadings in rivers originate from the discharge of population growth, as well as the extent of agricultural wastewater from manufacturing facilities. and industrial activities. In Asia, the domestic sector contributes 54 per cent The increase in BOD loadings is mainly driven to the total BOD loadings in 2010, of which about 29 by population growth, urbanisation, increasing per cent come from sewered sources and 25 per cent generation of industrial wastewater and livestock from non-sewered sources. Compared to the other production. With the help of model results it isnot continents, a high share of BOD loadings, namely 45 only possible to analyse the change in loadings over per cent, comes from wastewater produced in the time, but also to analyse the causes of high in-stream manufacturing sector.

Table 3.11: Categories of organic pollution loadings accounted for in total BOD loadings.

• Domestic sewered (point sources) • Domestic non-sewered-hanging latrines (point sources); Domestic septic tanks, pit toilets, open defecation (diffuse sources) • Manufacturing (point sources) • Urban surface runoff (diffuse sources) • Agriculture – livestock wastes (diffuse sources)

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Figure 3.16: BOD loadings for Latin America, Africa, and Asia for 1990 and 2010. Units: tons/year.

Figure 3.17: Distribution of BOD loadings according to source for 2010. Units: percentage.

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3.4 Salinity pollution and impairment of water use

3.4.1 What is salinity pollution and how does it can hinder the use of a freshwater supply for irrigation. impair water use? Only water with a relatively low salinity can be used Salinity pollution occurs when the concentration of for irrigation. If water applied to crops has a too high dissolved salts and other dissolved substances in rivers salinity concentration, salts accumulate in the root and lakes is high enough to interfere with the use of zone of plants and interfere with the plant’s extraction these waters. In freshwaters, salinity is commonly of water from the saline solution. A reduced water defined and measured as the mass of “total dissolved uptake can lead to wilting of the plant. While some solids” (TDS) in a litre of water, with units of milligrams plants are salt-tolerant, the majority of food crops per litre (mg/l).10 This is also the approach used in this are not. With this in mind, the Food and Agriculture report. Organization (FAO) has recommended limits to the use of saline water for irrigation (Table 3.12). Restrictions All freshwaters have a natural background level of on use for irrigation start at a concentration of TDS of salts due to the weathering of soils and rocks in their 450 mg/l, a concentration that is not unusual where drainage basin. In drainage basins underlain by granite, waste loadings are significant. the weathering rate is relatively low, and, accordingly, the natural level of salinity in rivers in such areas is Salinity pollution has wide-ranging negative impacts low. In drainage basins with clay soils, weathering on aquatic ecosystems at the individual, population, is much higher, and also water salinity tends to community, and ecosystem levels (Cañedo-Argüelles be proportionately higher. Close to the sea, rivers et al., 2013). Freshwater organisms have a limited acquire salt by mixing with tidal ocean waters or from tolerance to salinity and usually cannot adapt to precipitation containing traces of sea salt. Therefore, salinity concentrations significantly higher than even without human interference, some rivers have natural background levels. relatively high salinity levels. In these naturally saline Salinity pollution is also of concern to certain rivers and lakes, aquatic and riparian ecosystems have industries, such as food processing and pharmaceutical adapted to these saline levels. manufacturing because they require intake water with Society artificially increases the concentration of salinity very low salinity. High salinity levels also contribute to by discharging domestic, industrial, and agricultural scaling of pipes and boilers in factories (Salvato et al., wastes into rivers and lakes. As will be seen in Section 2003). 3.4.3, important anthropogenic sources of salinity Salinity pollution is a global problem but tends to be are irrigation return flows, domestic wastewater, and more severe in arid and semi-arid regions where the runoff from mines. A more local and seasonal source, dilution capacity of rivers and lakes is lower and the particularly important in developed countries in colder use of irrigation higher (Vengosh, 2003). climates, is the wash-off of salt used to melt snow on In this report, the FAO recommendations for irrigation roadways (Anning & Flynn, 2014). given in Table 3.12 are used as benchmarks for the Salinity pollution can have many important negative level of pollution. impacts. One of the most important impacts is that it

Table 3.12: Classes of salinity water pollution according to river concentrations of TDS used in this report. These classes correspond to the restrictions on use for irrigation from FAO (1985) shown in the third column.

Water pollution class TDS (mg/l) Restrictions on use for irrigation FAO (1985)

Low pollution < 450 No restrictions Moderate pollution 450–2,000 Increasing restrictions Severe pollution > 2,000 Severe restrictions

10Total dissolved solids include both dissolved salts as well as dissolved organic materials. According to the US EPA: “In stream water, dissolved solids consist of calcium, chlorides, nitrate, phosphorus, iron, sulfur, and other ions particles that will pass through a filter with pores of around 2 microns (0.002 cm) in size.” US EPA http://water.epa.gov/type/rsl/monitoring/vms58.cfm. Retrieved May, 2015. 37

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3.4.2 What is salinity pollution and how does it As was noted previously, faecal coliform bacteria impair water use? and BOD river concentrations vary from month to GEMSTAT analysis month because of the variability of river conditions. River salinity also varies in this way. Table 3.14 shows As for the analysis of faecal coliform pollution and the length of rivers affected by salinity pollution organic pollution (see Sections 3.1.2 and 3.2.2), there taking into account the month-to-month variation of are insufficient measurements on the continental scale river pollution. Around 4,600 to 10,000 km of Latin for Latin America, Africa, and Asia to gain a continental America’s rivers, or about 0.7 per cent of all river overview of salinity pollution based only on data. stretches, are in the severe pollution class. For Africa, Furthermore, the data distribution is geographically the estimate is around 32,000 to 83,000 km, or around biased because of the limited number of countries 4 per cent of its river stretches, and for Asia around providing information to the system. Therefore, as 28,000 to 65,000 km, amounting to about 3 per cent in previous sections, all TDS data from 2000 to 2010 of its entire river stretches. were consolidated in individual statistical distributions for each of the three continents (Figure 3.18 and Table Figure 3.20 shows the frequency of months in a year 3.13). in which river stretches are in the severe pollution category for TDS. In this context, it is assumed that While the medians are in the low pollution class, the river stretches with severe or moderate pollution six 90th percentiles for Africa and Asia are above or near months or more in a year are an indication of hot spot 450 mg/l. This indicates that 10 per cent or more of areas. the measurements from these continents have salinity levels that would restrict their use for irrigation to Figure 3.21 shows the trend in TDS river concentrations some degree. While Latin America has lower overall between the early 1990s and late 2000s. TDS measured levels of total dissolved solids, Figure 3.18 concentrations have increased in 21 per cent of the (left panel) shows that some measurements do exceed river stretches in Latin America, 33 per cent of the the 450 mg/l guideline value. river stretches in Africa, and 37 per cent of the river stretches in Asia. In total, 31 per cent of the river Modelling analysis stretches on these three continents have an increased Figure 3.19 shows an example of the level of TDS for TDS concentration. February 2008–2010 according to the classes of TDS The areas where salinity pollution has increased to in Table 3.12. Areas of severe salinity pollution exist a severe level of total dissolved solids or started at in the upper and lower Nile and Indus basins. Areas a severe level and became worse are of particular of moderate pollution (where use of river water for concern. These stretches are shown in Figure 3.21 and irrigation is partially restricted according to Table 3.12) can be considered another estimate of hot spot areas. include river stretches of the Euphrates, Ganges, and Aral Sea basin.

Table 3.13: Overview of data availability and statistical values for TDS in the period 2000–2010. Data source: GEMSStat. SD = Standard deviation. Units: [mg/l]

No. of stations/ No. of Continent Median 10th percentile th90 percentile SD 10,000 km² measurements

Latin America 0.04 2,901 52 19 223 119

Africa 0.012 1,687 333 118 1,014 1,820

Asia 0.045 7,441 70 8 445 2,936

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Table 3.14: Length and percentage of river stretches (km) in various salinity pollution classes. The minimum and maximum monthly stretches are indicated for the period of 2008 to 2010.

TDS concentration Latin America Africa Asia Water pollution class (mg/l) (min, max) (min, max) (min, max)

1,146,000–1,163,000 1,330,000–1,410,000 1,367,000–1,473,000 Low pollution x ≤ 450 95–96% 87–93% 86–93%

39,000–50,000 82,000–112,000 81,000–150,000 Moderate pollution 450 < x ≤ 2,000 3–4% 5–7% 5–10%

4,600–10,400 32,000 – 83,000 28,000–65,000 Severe pollution x > 2,000 0.4–0.9% 2–5% 2–4%

Figure 3.18: Box-and-whisker plots (left) of the distribution and cumulative frequencies (right) of TDS in Africa, Latin America, and Asia in the time period 2000–2010. Boxes show 25th to 75th percentile and median (black line). Data source: GEMStat.

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Figure 3.19: Estimated in-stream concentrations of total dissolved solids (TDS) for Latin America, Africa, and Asia for February 2008–2010. Bar charts show minimum and maximum monthly estimates of river stretches in the severe pollution class per continent in the 36-month period from 2008–2010 corresponding to data in Table 3.14.

Figure 3.20: Frequency (months/year) in which “moderate or severe pollution” levels of total dissolved solids occur in different river stretches over the period 2008–2010.

Table 3.15: Hot spot areas of salinity pollution (from Figure 3.20 and Figure 3.21).

• Lower Nile river basin • Euphrates river basin • Indus river basin • Ganges river basin • Aral Sea basin

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Figure 3.21: Trend of TDS levels in rivers between 1990–1992 and 2008–2010. River stretches marked with orange or red have increasing concentrations between these two periods. River stretches marked with red have an “increasing trend of particular concern” meaning that in these stretches the pollution level increased into the severe pollution category in 2008–2010, or that they were already in the severe pollution category in 1990–1992 and further increased in concentration by 2008–2010.

3.4.3 Sources of salinity pollution the fraction of irrigated area is small in Africa, TDS Most of the salinity loading to rivers, including in loadings from irrigation are much larger compared to Latin America, Africa, and Asia, comes from natural the other sources, e.g. manufacturing. Loadings from background sources (Figure 3.23, upper diagram). irrigation return flows may be underestimated for the In this study, background concentrations of TDS year 2010 because the extent of irrigated area in that are estimated to range from around 5 to 832 mg/l year has not been estimated (Siebert et al., 2015), and (Appendix B). However, about 10 per cent of river the coverage of irrigated area for these calculations is stretches have a natural TDS concentration of > 450 assumed to be constant between 2005 and 2010. On mg/l (defined here as “moderate” salinity pollution). all continents, the third most important source was Exceptions are some arid and semi-arid drainage domestic wastewater conveyed by sewers. basins with high weathering rates. But the high salinity Runoff from mining activities is an important source of areas indicated in Figure 3.19, Figure 3.20, and Figure salinity in some rivers. An example is given in Chapter 3.21 are almost all caused by anthropogenic loadings 4 for the River Vaal. However, it is not included here of total dissolved solids (Table 3.16). because of the lack of comprehensive data from the In both Africa and Asia, the main anthropogenic source three continents being studied. Therefore, in some is return flow from irrigated areas which transfers river stretches the loadings of total dissolved solids large amounts of salts from cropping areas to surface are underestimated. TDS loadings from mining will be waters (Figure 3.22 and Figure 3.23). The second most included in future studies. Road salt is an important important category is manufacturing. In Latin America source of total dissolved solids in North American the most important source is manufacturing, followed rivers (Anning & Flynn, 2014), but is not expected by irrigation return flows (Figure 3.23). This is because to be of major importance for the three continents the fraction of continental area devoted to irrigation studied here. in Latin America is small compared to Asia. Although

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Table 3.16: Categories of salinity pollution loadings accounting for total TDS loadings.

Figure 3.22: Anthropogenic sources of TDS loadings for Latin America, Africa, and Asia for 1990 and 2010. Units: tons/year.

Figure 3.23: Upper diagram: Distribution of total anthropogenic versus background input of TDS to rivers in Latin America, Africa, and Asia. Lower diagrams: Distribution of TDS loadings according to anthropogenic sources for 2010. Units: percentage.

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3.5 Eutrophication and nutrient loadings to large lakes

3.5.1 What are eutrophication and other water decomposition of organic material, or rock and soil quality problems in lakes? weathering. But in many lakes, anthropogenic inputs Lakes contain around 90 per cent of the liquid of nutrients greatly accelerate the natural process. freshwater on the earth’s surface (ILEC, 2011) and they This is sometimes called “cultural eutrophication”. If are an important source of water and food. However, temperature, light, and other conditions are sufficient, the ability of lakes to provide these and other ecosystem loadings of nutrients stimulate the rapid growth of services is threatened by infrastructure development, algae and other aquatic plants. When these large overfishing, invasive species, and in particular by water algae populations die off, they are decomposed by pollution. Water quality degradation in lakes takes bacteria, which deplete the oxygen resources of the different forms including eutrophication, pathogen lake, threatening the survival of fish and other aquatic contamination, organic pollution, and chemical organisms. Other impacts of eutrophication in lakes pollution. In this study, the focus is on eutrophication are listed in Box 3.5. because of its negative impacts on lakes, its worldwide There is a lively discussion in the scientific community scale, and because it may be expanding in scope (e.g. about the importance of phosphorus and nitrogen Jin et al., 2005). A few of the many examples of lakes loadings as causes of lake-eutrophication.11 In this affected by eutrophication now or in the past are report only the total phosphorus loadings to lakes are shown in Table 3.17. taken into account. These loadings were examined in Eutrophication in lakes is part of a natural process 25 “major lakes” in the world selected because they are of nutrient accumulation that leads to gradually of special interest to human society due to their size.12 increasing the plant productivity of a lake. In this case, Some of these lakes are subject to eutrophication as nutrients originate from natural sources such as the noted in Table 3.17.

Table 3.17: A selection of past and present eutrophication problems reported for large lakes.

Lake Main source of nutrient pollution Selected effects of pollution Reference Phytoplankton changed from Chemical and manufacturing diatom flora to one dominated Taihu (China) plants, agriculture, domestic Stone (2011) by cyanobacteria; algae blooms; waste water Macrophytes disappeared Increase in phytoplankton biomass, Agriculture, industrial waste algae blooms, eutrophic and water, domestic waste water; Allinger and Erie (Canada, USA) hypereutrophic species, fish kills due reduced phosphorus inputs by Reavie (2013) to anoxia; water quality has been mid 1980s improving since the 1980s.

Low oxygen concentrations, algae Constance (Germany, blooms (re-oligotrophication since the Agriculture, domestic IGKB (2002) Austria, Switzerland) 1980s due to massive reduction of nutrient pollution)

Agriculture, domestic, Low oxygen concentrations, algae Kangur et al. Peipsi (Estonia, Russia) manufacturing blooms (2005)

Algae blooms (lake wide algae bloom Laguna de Bay Domestic, agricultural, industrial in 1979), low oxygen concentrations ILEC (2005) (Philippines) effluents which endanger aquaculture Phytoplankton changed from diatom flora to one dominated by Victoria (Tansania, Growth of the predominantly rural cyanobacteria; increase of algal Sitoki et al. (2010) Uganda, Kenia) human population; agriculture biomass; fish kills; more prevalent deep water anoxia; superposition effects by Nile perch introduction

11On the one hand, most scientists agree that under pristine circumstances phosphorus limits the growth of algae. This implies that excess phosphorus causes eutrophication and that its removal from lakes would in turn reduce eutrophication. On the other hand, others believe that in addition to phosphorus, nitrogen also plays a significant role depending on the type of lake, its trophic status, and the season (Kolzau et al., 2014). Still others believe that nitrogen rarely contributes to lake eutrophication (Schindler, 2012). 12The “major lakes” sample is made up of 5 of the largest lakes in each of five UNEP “Global Environment Outlook” regions (Africa, Asia, Europe, Latin America, and North America), excluding the Caspian Sea, Aral Sea, and Lake Chad because of their special characteristics. The 25 major lakes are displayed in Figure 3.24 to Figure 3.26. 43

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Box 3.5: Effects of eutrophication on lakes and reservoirs (from Smith et al., 1999) • Increased biomass of freshwater phytoplankton and periphyton • Shifts in phytoplankton species composition to taxa that may be toxic or inedible (e.g. bloom-forming cyanobacteria) • Changes in vascular plant production, biomass, and species composition • Reduced water clarity • Decreases in the perceived aesthetic value of the water body • Taste, odour, and water supply filtration problems • Possible health risks in water supplies • Elevated pH and dissolved oxygen depletion in the water column • Increased fish production and harvest • Shifts in fish species composition ardstow less desirable species • Increased probability of fish kills

3.5.2 What are the phosphorus loadings to Lake in Kyrgyzstan (211 kg P/km²/yr) are the highest major world lakes? loadings to the selected major world lakes (Figure Anthropogenic loadings of phosphorus into lakes 3.24). The loads to Great Bear Lake and Great Slave originate from domestic sewered wastewater, Lake in North America are very small. The phosphorus domestic non-sewered sources, manufacturing, loads to African lakes range widely, as do the loads to inorganic fertiliser from cropland, animal wastes, Asian lakes. It is important to note that the size of the and atmospheric deposition. Estimates for the time phosphorus load is not necessarily proportional to the period 1990–2010 are provided by the WorldQual degree of eutrophication because other factors have model, which was also used earlier in this chapter for an important influence on eutrophication including estimating faecal coliform bacteria, BOD and TDS in temperature and light conditions, the physical rivers (see Appendix B). A fraction of these loadings attributes of a lake, and average residence time of lake is assumed to be retained in the watershed of the water. lake and not enter the lake proper. Loadings of total The natural long-term processes of eutrophication are phosphorus computed by the model have been tested accelerated by anthropogenic inputs of phosphorus. against independent estimates of various lakes and Therefore, it is of concern that in 23 out of the 25 major large river basins (Appendix B). lakes more than 50 per cent of the total phosphorus The anthropogenic total phosphorus loads to Qinghai loads are from anthropogenic sources (yellow and red Lake in China (514 kg P/km²/yr) and to Issyk-Kul circles in Figure 3.24).

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Figure 3.24: Average total phosphorus loads per unit lake basin area and an indication of the anthropogenic versus background loadings for the selection of 25 largest lakes for the period 2008–2010. The size of a circle represents the annual total phosphorus load per unit lake basin area. The colour indicates whether the proportion of anthropogenic loadings exceeds 50 per cent (yellow circles) or even 90 per cent (red circles) of total loadings or falls below 50 per cent of total loadings (blue).

3.5.3 What are the sources of phosphorus? 3.26. Most of the major lakes in Latin America, Africa To avoid or reduce eutrophication in these lakes it is and Asia have increasing anthropogenic loadings. By necessary to know what sources of anthropogenic contrast, loadings decreased in North America and phosphorus are most significant (Figure 3.25). The Europe. Reductions in Western Europe and North dominant source in almost all lakes examined here is America were achieved through reduced usage of inorganic fertiliser. Livestock wastes are the second phosphorus containing products (e.g. detergents), largest source in Africa. Domestic wastewater is an a higher level of wastewater treatment and reduced important source of total phosphorus loadings in fertiliser application. However, fertiliser application is Europe and North America. still increasing in South America, in Africa, and in the Asia-Pacific region. The changes in estimated loadings between the periods 1990–1992 and 2008–2010 are shown in Figure

Figure 3.25: Sources of anthropogenic total phosphorus loadings to major lakes. The average percentage contributions to the annual loading for the period 2008–2010 are shown.

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Figure 3.26: Total phosphorus loadings from anthropogenic sources per unit lake basin area for 1990–1992 and 2008–2010. Units: kg/km²/year.

These trends in phosphorus loadings may change the small volumes and therefore shorter residence times. trophic state of a lake (the state of a lake according Larger lakes, as in the 25 lakes examined here, have to the availability of nutrients for aquatic flora). How much longer residence times (e.g. 330 years for Lake quickly a lake responds to an increase or decrease in Baikal and 23 years for Lake Victoria), and therefore it phosphorus inputs will depend, among other factors, might take decades or centuries for a lake to respond to on the residence time of a lake (the time it takes changes in phosphorus inputs. Box 3.6 below illustrates the water in a lake to renew itself). Small lakes will a feasible method for estimating the response of small respond fairly quickly because they have relatively to medium sized lakes to phosphorus inputs.

Box 3.6: Estimating the changes in the trophic state of lakes The predicted total phosphorus (TP) loads from a lake’s basin can be used to classify the corresponding trophic state of the water body by calculating the average equilibrium TP concentration in relation to threshold levels for trophic states according to Vollenweider (1976) (see Figure 3.27). For this plot, small to medium-sized lakes in different continents of the world with coherent data on P loading, lake surface area, and hydrology were selected, which allowed for the calculation of the equilibrium P concentration in the lake as the primary determinant of the trophic state (vertical axis). The horizontal axis represents the hydraulic load (calculated by dividing the annual inflow to the lake surface area) of the system and, therefore, characterises the hydrological setting of the system. Furthermore, the two time series periods from 1990–1992 and 2008–2010 were compared to identify trends. Most systems showed similar hydraulic loads, except of Lake Taihu and Kariba Reservoir, but marked differences in lake phosphorus concentrations. While European lake systems were predominantly characterised by decreasing P concentrations, most non-European systems showed increasing trends in P concentrations. In case of Lake Constance, Lake Como, and Lake Peipsi even a transition from eutrophic to mesotrophic conditions could be seen indicating the efficiency of water management programs. Thus, this method can be used for analysing the trajectories of changes in the trophic states of lakes and estimating the relevance of hydrological or water quality related drivers. The plot also illustrates that a large change in TP load does not necessarily need to be associated with a changing trophic state since certain threshold P concentrations have to be reached. The plot also allows for the estimation of a “distance to target”. The reduction in TP loadings required to reach mesotrophic conditions for Lake Taihu, for example, would be much larger than for Kariba Reservoir.

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A prerequisite for a wider application of this method is an objective survey of lakes of different sizes in a geographic area and requires further hydrological and limnological information including reference trophic states. It must also be stressed that a thorough testing of the phosphorus loading concept is required since this methodology was predominantly developed on temperate lakes and its application to tropical systems needs to be carefully assessed. These aspects are proposed to be part of the full scale World Water Quality Assessment to test the usability of this approach for a global assessment of lake eutrophication.

Figure 3.27: Trophic classification of 10 large lakes based on the phosphorus loading model by Vollenweider (1976). Two different periods were used (1990–1992 and 2008–2010) and the simulated TP loadings converted to the corresponding equilibrium phosphorus concentration (y-axis). Critical P concentrations of 10 and 25 mg/m3 for the transition between oligo-/mesotrophic and meso-/eutrophic systems, respectively, were used. Note the log-log plot.

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4 Water Pollution in River Basins

Aim of this chapter Identifying transferable messages about the world water quality situation with the help of eight river basin case studies. Main messages • Similar kinds of water quality challenges are occurring around the world even if the locations and situations are very different. But these challenges sometimes have different immediate and ultimate causes, all linked to unsustainable growth or practices. • A key to managing water quality is good governance and effective institutions. Barriers to good governance are the fragmentation of authority, lack of technical capacity, and lack of public awareness. These and other barriers can be overcome with action plans, collaborative authorities, and other instruments. • Coping with the global water quality challenge is closely connected to many other priorities of society such as food security and health. Therefore, actions to protect water quality should be part of efforts to achieve the new Sustainable Development Goals.

4.1 Introduction

After reviewing the water quality situation on three done either to restore water quality or to avoid further continents in the previous chapter, the water quality water quality degradation. The Upper Tietê case, for situation in eight river basin case studies from around example, demonstrates how much time it takes from the world (Figure 4.1) is examined in more detail in realizing the problem exists to the first signs of water this chapter. These cases emphasise the diversity of quality improvement. water quality issues (Table 4.1), management actions, Each case study first presents an overview of the river and lessons learnt from experience in different river basin’s physical and governance characteristics. It basins. Examples from the Hudson and Elbe rivers then reviews the nature of its water quality problems show the complete trajectory from articulating a water and the current solutions being planned or tried out. pollution problem through to its solution. Most of the Finally, it describes the lessons to be learned from the examples, however, show that much still needs to be case study that are relevant to other river basins.

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Chapter 4.2 River Basin 1 – Upper Tietê | Confluence of Tietê and Pinheiros Rivers in São Paulo, Brazil Source: Ricardo Zig Koch Cavalcanti / Banco de Imagens ANA

Chapter 4.3 River Basin 2 – Godavari | Sunset at Godavari Source: https://commons.wikimedia.org/wiki/File:Sunset_at_Godavri.JPG

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Chapter 4.4 River Basin 3 – Volta | Transporting sand upstream the Volta for construction Source: Adelina Mensah

Chapter 4.5 River Basin 4 – Chao Phraya Source: Dr. Pinida Leelapanang

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Chapter 4.6 River Basin 5 – Vaal River | Vaal Barrage Source: Gordon_O’Brien

Chapter 4.7 River Basin 6 – Medjerda River Source: Seifeddine Jomaa

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Chapter 4.8 River Basin 7 – Elbe River | Valley of Elbe near Děčín. Source: https://commons.wikimedia.org/wiki/File:Labe_udoli.jpg

Chapter 4.9 River Basin 8 – Hudson River Source: Matthias Manske | https://de.wikipedia.org/wiki/Hudson_River#/media/File:Hudson_South.jpg

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Figure 4.1: Case study locations.

Table 4.1: Case study overview (BOD = biochemical oxygen demand, FC = faecal coliform bacteria, TDS = total dissolved solids, N = nitrogen, P = phosphorus, PCBs = polychlorinated biphenyls).

Continent River Basin Typical water quality issue

Latin America Upper Tietê Organic pollution (BOD) Asia Godavari Organic pollution (BOD) Africa Volta Pathogen pollution (FC) Asia Chao Phraya Pathogen pollution (FC) Africa Vaal Salinity pollution (TDS) Africa Medjerda Erosion and leaching of salts (TDS) and nutrients Europe Elbe Nutrients (N and P) North America Hudson Synthetic organic chemical pollution (PCBs)

4.2 River Basin 1 – Upper Tietê

The Upper Tietê River flows through the São Paulo Metropolitan Region, south-eastern Brazil, the largest urban and industrial agglomeration of South America. Since the 1950s, the growth of the population and the industrial activities led to a severe deterioration of the Tietê River water quality. In 1991, a Cleanup Programme was launched, and since then, the treatment level of domestic and industrial sewage has significantly increased. The river stretch impacted by severe pollution downstream of the São Paulo Metropolitan Region has decreased from 260 km to 100 km. This is the largest river cleanup project in Brazil and shows the importance of public participation, continuous investments, and the creation of governance and financing mechanisms.

4.2.1 Brief overview of Upper Tietê Basin municipalities, together responsible for 19 per cent of characteristics and governance Brazilian GDP. The Tietê River has a total length of 1,136 km and is The hydrology of the basin is very complex because a tributary of the Paraná River, which is part of the of many structures for flood control, water supply Plata Basin, the second largest basin in South America. and flow management that have changed the natural It is located entirely within São Paulo State, south- regime of water flow. Human water consumption eastern Brazil. The Upper Tietê River flows through is larger than the water available in the basin, and a the São Paulo Metropolitan Region, the largest large portion of water (31 m³/s) has to be imported urban and industrial agglomeration of South America from neighbouring basins. which includes the city of São Paulo and 38 adjacent

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Upper Tietê River Basin River Length: 243 km Drainage area: 5,720 km² (37% urban) Population: 20 million (2010) Precipitation: 1,400 mm

Figure 4.2: Location of the Upper Tietê River Basin.

Water quality management in the basin is the chemicals are observed in the Upper Tietê River, responsibility of several agencies. Water quality indicating the high contribution of domestic and is monitored by São Paulo Environment Agency industrial wastewater (CETESB, 2014). The total (CETESB), which also has the mandate for water domestic organic load in the river is 635 ton BOD/day. pollution control. The São Paulo State Sanitation The industrial organic load is 26.4 ton BOD/day and Company (SABESP) is in charge of domestic water the industrial inorganic load is 307 kg BOD/day (FUSP, supply and wastewater treatment in most of the 2009). municipalities of the basin. The Upper Tietê River Because of the high BOD loads, the section of the Tietê Basin Committee was established in 1991 and has, River that runs through the São Paulo Metropolitan among other responsibilities, the task to approve the Region frequently has dissolved oxygen concentrations River Basin Plan and water quality targets. Civil society, below 2 mg/l, and many tributaries have values close NGOs, and the media have played an important role to 0 mg/l. Fish surveys carried out in the river showed in the creation and implementation of the Tietê River a significant reduction of fish diversity as the river Cleanup Program, described later. flows into the urban areas, and a complete absence 4.2.2 Typical water pollution problem, causes of fish when it flows through the city of São Paulo and impacts (Barrella & Petrere, 2003). Over the last 50 years, an intense urbanisation The uncontrolled growth of the São Paulo Metropolitan process has taken place in Brazil. The population of Region around two major reservoirs (Billings and the São Paulo Metropolitan Region has increased Guarapiranga) has degraded water quality because of sevenfold since 1950 and its growth was not followed the release of sewage, garbage, and diffuse pollution. by a proportionate increase in domestic wastewater The eutrophication of these reservoirs is a concern treatment levels. The intense industrialisation process for public water supply, requiring the use of algicides that occurred during that period also contributed to to control the high levels of algae, and increasing the the increase of water pollution. The location of the São costs of water treatment. Paulo Metropolitan Region on the upstream reaches Irrigation with polluted water is also a concern on of the Tietê River is also an important factor, since the farms because of the contamination of farm produce. relatively low river discharge here affords only a low Pinheiros River, a tributary of Tietê River, is a large dilution capacity for pollutants. urban breeding ground of mosquitoes. Insecticides are In the 1950s, fishing, rowing, and swimming were applied in the river margins to eliminate mosquitoes important activities at the Tietê River and many clubs and other vectors, and traces of these insecticides were created along the river, some of which still exist. were found on the waters of Pinheiros River (Cunha However, since 1972 the high pollution levels in the et al. 2011). river have discouraged these activities. The São Paulo Metropolitan Region is affected by the High concentrations of BOD, phosphorus, ammonia- heat island effect that contributes to the formation nitrogen, pathogenic microorganisms, and toxic of convective storms of high intensity, causing floods

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in small urban watersheds and extensive runoff a challenge, as some households were unconnected to that contributes to a significant pollution load. sewers because people were unable to pay. In these Downstream of the São Paulo Metropolitan Region cases, the State government decided to pay for these water pollution causes the formation of excessive connections. foams from detergents, the accumulation of debris, With regards to industrial pollution, the CETESB and unpleasant odours. identified 1,250 companies in 1992 that were 4.2.3 Solutions and transferable lessons responsible for 90 per cent of the industrial pollution In the late 1980s, NGOs and the media organized of the Tietê River. These companies were asked to several actions against the Tietê River degradation and submit plans for constructing treatment systems and a campaign to clean up the river. In 1991, a petition were supported through loans from the World Bank calling on the State government to clean-up the Tietê and the Brazilian Development Bank (BNDES). The River was signed by 1.2 million people and in 1992 the financing of these plans and imposing of fines between São Paulo State Government launched the Tietê River 1992 and 2008 led to a 93 per cent reduction of the Cleanup Program. The programme is funded through industrial organic load and a 94 per cent reduction of loans from the InterAmerican Development Bank and its inorganic load (CETESB, 2008). Brazilian Development Bank, and from resources of The main result of the increase in the treatment the SABESP. The programme includes the construction of domestic sewage and industrial effluents wasa of new wastewater treatment plants, expansion decrease of the downstream river reach impacted of existing plants, construction of sewer collection by pollution. In 1992, a total length of 260 km was networks, and the control of industrial pollution. affected downstream of the São Paulo Metropolitan The programme was divided into three phases with a Region. In 2014, this was reduced to 100 km. These total investment of US$ 3.6 billion. The programme is improvements contributed to the return of fish at currently in its third phase, and will finish in 2016. A some locations and the reduction of unpleasant fourth phase is planned with a total investment of US$ odours. 1.9 billion and the goal to universalise the collection Despite the improvement in water quality downstream, and treatment of sewage in areas attended by the the river in the São Paulo Metropolitan Region is still SABESP. highly polluted. The recovery of the Tietê River is a long Since 1992, the level of sewage treatment of domestic process that will need continuous investments over wastewater has increased significantly from 24 the next years. The Tietê River Cleanup Programme to 84 per cent (Figure 4.3). Sewage collection has is the largest river cleanup project in the country and increased from 70 to 87 per cent. The expansion of shows the importance of public participation and the sewage collection networks in poor regions has been provision of financing mechanisms.

Percentage of treated sewage

Figure 4.3: Trend in percentage of domestic sewage treated in the Upper Tietê River Basin (SABESP, 2014).

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4.3 River Basin 2 – Godavari

In the Godavari river basin, discharge of untreated and partially treated sewage from cities is one of the principal reasons for the river’s non-compliance with Indian water quality criteria. A Location Importance Index (LII) has been developed to assess the extent and severity of violations of water quality standards. A High LII indicates frequent pollution stress and thus a need for conducting a detailed pollution inventory and expanding water quality monitoring.

4.3.1 Brief overview of Godavari Basin (responsible for ground water estimation, qualitative characteristics and governance and quantitative studying and approval of groundwater The Godavari River is the second longest river in abstraction), the State Water Resources/Irrigation India and it has the third largest river basin in the Departments (responsible for the approval of surface country. Godavari originates from Trayambakeshwar water withdrawal from river systems), and the Urban in Maharashtra and then flows for about 1,465 km in Local Bodies (responsible for water withdrawal from a generally south-eastern direction before emptying surface/groundwater bodies, treatment and supply, and into the Bay of Bengal. The catchment basin area of treatment of sewage). There is only a modest amount the river is 312,812 km2 with agricultural land and of information sharing and/or cooperation between forest as the main land use categories in 2005-06 these agencies (Central Water Commission, 2012). (60 per cent and 30 per cent of the catchment area, 4.3.2 Typical water pollution problems, causes respectively) (CPCB India, 2011). Despite its massive and impacts catchment area, the river’s discharge is not substantial At several locations, the water quality of the Godavari because of the low average annual rainfall in the River does not meet the required criteria for Class basin. Its four important tributaries are the Manjira, A (“Drinking Water Source without conventional the Pranhita, the Indravati and the Sabari. treatment but after disinfection”) including for the Water is a State subject in India, i.e. the State is parameter biochemical oxygen demand (BOD). Figure responsible for the management of water resources. 4.5 summarizes the long term trend of BOD from Responsibilities for water management are shared several monitoring stations in the river. While there between the State Pollution Control Boards is a variation in the peaks, mean BOD levels are more (responsible for surface and groundwater quality and or less constant. industrial discharges), the State Groundwater Boards

Figure 4.4: The Godavari Basin extends across the States of Maharashtra, Karnakata, and Andhra Pradesh.

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Discharge of untreated and partially treated sewage to pulp & paper and fertiliser companies. These from cities is one of the principal reasons for the non- industries are likely to be massive water consumers compliance. The sources of water pollution include and contributors to the deterioration in water quality (a) domestic sewage, (b) industrial effluent, and (c) in the river particularly from Nashik to Nanded agricultural non-point sources. The population density in Maharashtra and at Baster in Chhattisgarh and in the basin ranges from 25–50 persons/km2 to 500– Burgampahad in Andhra Pradesh (CPCB India, 2011). 2 1,000 persons/km . More than 441 towns, 58,072 Pollution due to the runoff of chemical fertilisers is settlements and 33 cities are located in the basin also likely to be a problem. The average annual use area. The population of the basin, based on a 2001 of chemical fertilisers in the basin area is 49.34 kg/ha census, was 60.57 million, out of which about 75 per which is more than twice the national average. The cent live in rural and the other 25 per cent in urban total consumption of pesticides is 21,586 t/yr. areas. Nearly 40 per cent of the workforce is engaged 4.3.3 Solutions and transferable lessons in cultivation, 30 per cent as agriculture labourers, In the Godavari basin, there are 34 water quality and 30 per cent in mining and manufacturing and monitoring stations spread across the States of other industries (Central Water Commission, 2012). Maharashtra and Andhra Pradesh. The Water Quality In the absence of a detailed effluent inventory, the Index (WQI, Abbasi & Abbasi, 2012) is used as a sewage load entering the Godavari is calculated based single parameter to (a) communicate water quality on certain assumptions. Assuming approximately 80 to stakeholders and (b) compare water quality across litres of sewage generation per person in urban areas locations over time. CPCB in India has adopted the and approximately 50 litres sewage in rural regions, WQI from the index developed by National Sanitation the volume of raw sewage entering Godavari will be Foundation (NSF) USA. CPCB’s WQI uses parameters approximately 3,000 million litres per day. Further such as BOD, DO, faecal coliform bacteria (FC), and pH. assuming an average BOD concentration of 200 mg/l The WQI used so far is based on concentrations and and an average treatment capacity of 40 per cent, the does not account for the adequacy of river flow for total BOD load can be estimated at 219,000 t/yr. This diluting wastes and supporting the aquatic ecosystem. would correspond to an average BOD intensity of 409 It would be useful, therefore, to introduce minimum kg/km/day of river length. “environmental flows” as an additional benchmark for No direct estimate of effluent generation in the tracking the health of the Godavari. Godavari basin or effluent entering the Godavari has As assessment of compliance is one of the key been made or is available in literature. In Andhra objectives of the water quality monitoring program, it Pradesh (situated in the lower Godavari basin), sugar is useful to develop metrics to prioritise the monitoring and distillery units are large in number in addition

Water quality (BOD) trend of Godavari River

Figure 4.5: Water quality (BOD) trend between 2002 to 2011 in the Godavari River (CPCB India, 2011).

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locations. To achieve this objective, a new Index called stations. These measures have been recommended to Location Importance Index (LII) was developed. The LII the Maharashtra Pollution Control Board. is a measure to assess the extent (frequency), severity There is a need for conducting comprehensive (magnitude) of violations and how contiguous the impact assessment going beyond the assessment of violations are in relation to standards. To calculate in-stream water quality. Such an assessment should LII, monthly BOD and DO observations from 18 water cover the entire river basin ecosystem. For a holistic quality monitoring stations in the State of Maharashtra impact assessment, parameters such as water use are used. High LII values, e.g. in the stretch downstream (domestic, industrial agricultural) non-point pollution of the city of Nasik, indicate frequent pollution stress loads, agricultural yield, public health indicators, and thus a need for conducting a detailed pollution groundwater quality, ground water levels, biodiversity, inventory and initiating water quality control and top soil contamination should be considered measures. Further, these stretches are ideal for the including climate change related vulnerability. placement of automated water quality monitoring

4.4 River Basin 3 – Volta

The resources of the Volta River basin of West Africa are essential to the livelihoods of the predominantly rural communities that inhabit it. Due to limited sanitation infrastructure, faecal coliform contamination has already deteriorated water quality in parts of the basin and this will continue to escalate with increasing population and urbanisation. Transboundary management structures, participatory processes and other innovative solutions are suggested as short and medium term remedies.

4.4.1 Brief overview of Volta Basin international conventions, membership in the Economic characteristics and governance Community Of West African States ECOWAS, as well The Volta River basin has a rich network of diverse as the West African Economic and Monetary Union ecosystems that provide a wide range of natural (Ghana excepted). Traditional management systems are resources for its six riparian countries. These resources also important, even though the complexities between directly and indirectly support the livelihoods and modern and customary systems can sometimes lead to economic development of its current population of conflicts (UNEP-GEF Volta Project, 2013). over 20 million. With populations projected to reach Brief facts about the Volta River Basin (Source: UNEP- 33 million by 2025 and with increasing variability and GEF Volta Project, 2013): changes in weather patterns in the basin (Oyebande • Situated in the sub-humid to semi-arid West African and Odunuga, 2010), the sustainability of basin Savannah Zone and covering 28% (400,000 km2) of resources, especially water (McCartney et al., 2012), is West Africa; under severe and increasing threat. • Shared by: Benin (4.1%), Burkina Faso (46%), The creation of the Volta Basin Authority (VBA) in 2006 Ghana (39%), Côte d’Ivoire (1.8%), Mali (2.4%), and and the Convention on the Status of the Volta River and Togo (6.4%); the Establishment of the Volta Basin Authority (signed • Drained by 4 sub-basins: the Black and White in 2007, ratified by the six countries in the period 2008- Voltas (from Burkina Faso), Oti River (Benin), the 2009) is a transboundary approach towards coordinated Lower Volta (Ghana), and emptying into the Gulf management of the basin’s resources. The VBA has of Guinea; overall responsibility for implementing an international • The Volta Lake in the Lower Volta, created in 1965 cooperation for the sustainable management of water by the construction of the Akosombo Dam for resources and promoting better sub-regional economic hydropower is the 2nd largest man-made lake by integration (VBA, 2010). In addition to the VBA mandate, surface area (8,500 km2) in the world; the management of the Volta Basin is characterised by a number of international, regional and national • Precipitation variesbetween 1,600 mm (south) and bureaucratic structures, such as ratification of various 360 mm (north);

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• Annual runoff is 56.4 billion m3; shallow wells that are a preferred source of drinking • Population density: 72/km2 in 2010; 83/km2 in water are highly polluted with coliforms exceeding 2015; >100 inhabitants per km2 by 2025; 1x103 cfu/100 ml for E. coli and 1x104 cfu/100 ml for faecal coliforms (Boubacar et al., 2013). In Burkina • Main livelihoods: agriculture (extensive and mostly Faso and northern Ghana, run-off from inland port rainfed), livestock production, fisheries, forestry, communities and urban settlements near river banks and hunting and gathering. and reservoirs also significantly affect water quality. 4.4.2 Typical water pollution problem, causes Rural households in the basin mainly depend on and impacts individual or communal latrines or defecate openly Available data indicates that severe water quality in nearby bushes or river banks. In urban areas, the deterioration is not widespread in the Volta Basin. sewerage systems are only able to service a small Significant localised problems are more prevalent in portion of the population and, as a result, untreated the densely populated northern towns which have sewage is discharged directly into the environment in lower hydrological flows than the south, where the a number of larger cities such as Ouagadougou, Bobo higher flows dilute pollutants (UNEP-GEF Volta Project, Dioulasso, and Abidjan. In Ghana, national assessments 2013). Although requiring more extensive and long- identified 70 decentralised wastewater and faecal term datasets to be conclusive, reports of surface sludge treatment plants serving less than 10 per cent water quality in the basin indicate generally good water of the urban wastewater volume, and of these, only 13 quality (e.g., Andah et al, 2003; Goes, 2005; WRC, 2008) per cent were still operating (Murray & Dreschel, 2011). with low average nutrient levels, especially in the Volta In studies assessing the quality of effluent into the Volta Lake (van Zweiten et al., 2011). High nutrient loads from River, an effective reduction of BOD concentrations and agricultural sources occur in specific locations such as total removal of coliform (99.99 per cent) was shown cotton, sugar cane, or commercial oil palm plantations in one study (Hodgson, 2007), whilst another showed (Programme GIRE Burkina Faso, 2001; Samah, 2012) that, although the treatment performance of two or from markets (Ofori, 2012), and, to a lesser extent, treatment facilities significantly reduced coliform by 95 localised industrial pollution from beverage and textile per cent, the final effluent still did not meet the Ghana production (Gampson et al., 2014). Faecal coliform EPA standards and required final disinfection (Kagya, levels are, however, consistently above WHO guidelines 2011). for drinking water (e.g., Kankam-Yeboah & Opoku- The concentration of FC can be influenced by seasonal Duah, 2000; UNEP-GEF Volta Project, 2013). Samah changes, with high contamination levels at the onset (2012) reports levels between 121±32 cfu/100 ml and of heavy rains where runoff carries raw sewage and 425±181 cfu/100 ml in the Asukawkaw River for March- leachate from waste dumping sites into the water June 2012 that contributes about 40 per cent to the bodies. The construction of small, medium and large total volume of the Volta Lake. reservoirs in the basin, primarily used for irrigation, The presence of faecal coliform bacteria in the basin the anticipated rainfall variability and the decrease have been attributed to increasing domestic inputs in average annual basin flow of approximately 24 per from discharge of waste, untreated sewage, and open cent and 45 per cent by 2050 and 2100, respectively defecation along the banks of the Volta River by both (McCartney et al., 2012; Sood et al., 2013), will humans and grazing animals, including in some areas, have serious hydrological and health implications large flocks of migratory birds (Abdul-Razak et al., 2009). due to lower dilution flows and increased pollutant In most parts of the basin, a major economic activity is concentrations. the extensive production of livestock at high densities The faecal contamination of water in the Volta (although this tends to decrease from the north at 10 basin has important implications for urban and rural to 20 animals per km2 to the south at 1 to 5 animals per water supply. The Volta Lake, for example, is a water km2), which has impacts on water quality (UNEP-GEF reservoir for large cities such as Akosombo; and rural Volta Project, 2013). In Mali and Burkina Faso, surface communities depend directly on the surface water as water quality is poor with numerous coliform and they tend to have less access than urban communities bacillus bacteria. In the Sourou Valley of Burkina Faso, to potable water from boreholes, pumps, or piped

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water taps. Burkina Faso and Ghana have a largely it has, which allows for access and collaboration with rural population. So, only 37 per cent (in Burkina Faso) reputable international and national institutions, to 62 per cent (Ghana) of households have access to projects and programmes. Existing networks of safe drinking water (Rodgers et al., 2007). Even where institutions can be enhanced, or new networks created, there is access, a large number of people still prefer and to enable the development and implementation of continue to use untreated water from the river due to both regional and national management solutions. quality perceptions and opportunity costs (Engel et al., The independent development of national strategies 2005). by individual countries is less efficient than a As a result, waterborne diseases are a threat to the comprehensive regional strategy. However, as this will rural communities, with a significant contribution to the require time and funds, the sharing of best practices 2012 mortality rates of children aged less than 5 years in by the countries is needed at this time. A database of Benin (10 per cent), Burkina Faso (11 per cent), Ghana (7 related information generated through regional, cross- per cent), Côte d’Ivoire (10 per cent), Mali (12 per cent), basin, and national research can support this process. and Togo (9 per cent) (WHO, 2014a). Contaminated A harmonised method of water quality monitoring water also has implications for aquatic organisms such techniques, including faecal source tracking, can also as clams, a common and inexpensive source of protein provide important information required for evidence- and livelihood for the communities at the Volta estuary. based decision making. Adjei-Boateng et al. (2009) and Amoah et al. (2011) The VBA also encourages countries to financially found that the clam Galatea paradoxa in these areas support improved sanitation and water pollution was highly contaminated with FCs, due to its capacity control. This includes increasing the technical and to accumulate up to five times the bacterial load in the institutional capacity to collect and interpret relevant surrounding water, through its filter feeding activities. data, formulate policy, and implement strategies. The evidence of high microbial contamination of fish Integrated water resources management requires caught in polluted waters (Kombat et al., 2013), making participatory frameworks and processes at all levels it unsafe or undesirable to eat, shows that there are to succeed. Institutions from government, civil society potential impacts to the health and livelihoods of the (including traditional authorities), academia, and the local communities. private sector need multi-stakeholder platforms to Water contamination by FCs is compounded by communicate, support each other, and coordinate poor awareness and education about public health, activities. At the local level, community engagement, inappropriate technologies for sanitation, both in urban especially by beneficiaries, and the use of indigenous and rural areas, lack of effective and coordinated legal knowledge, where appropriate, will lead to acceptance systems for controlling the discharge of effluents and and success. The appreciation of gendered roles in water lack of financial resources. The capacity to address use and sanitation is also essential in the development such issues is challenged both at the regional and of management strategies (e.g., Peter, 2006; Figueiredo national levels by (i) limited research and technical and Perkins, 2013). capacity, (ii) inadequate implementation of regulations, Currently, solutions for effective water management in (iii) complexities of ecosystems and poverty, (iv) the Volta Basin tend to focus on strategies for improving the language barrier between Anglophone and sanitation and the provision of safe drinking water. Francophone countries, and (v) lack of effective and These strategies are applied in addition to traditional operational institutional and legislative mechanisms wastewater treatment systems at community and to ensure basin wide action, as well as other factors. household levels for reducing pathogen loading into the However, there are still a number of opportunities environment. Potential innovative on-site technologies, and transferable lessons in terms of governance, such as anaerobic digestion and biogas generation information flow and technological solutions, which (Avery et al., 2014), the application of low-tech options can be used for integrated water quality improvements. using locally available biomaterials, or ecosanitation, 4.4.3 Solutions and transferable lessons where urine and faecal matter are separated to recover nutrients (Mihelcic et al., 2011); could also be explored. The advantage of having the VBA as a management structure is the regional recognition and respect that

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A range of small scale water treatment technologies, eventually abandoned because community members from low cost chlorine disinfection systems to more were not aware of the full capital and operational costs expensive reverse osmosis systems, appropriate storage from the start (Rossiter et al., 2010). of water and improved hygiene are required to minimise In addition to the numerous opportunities for addressing the potential health impacts of drinking contaminated water quality issues of the Volta Basin, promoting water. Local ingenuity and simple mechanisms also community and household level solutions has far- improve access to safe drinking water; for example, the reaching impacts in protecting the health of humans SODIS method of placing clear bottles filled with water and the ecosystem. Education and awareness creation on a piece of metal in full sunlight for a number of hours processes are, therefore, required to build knowledge kills off all microbes (McGuigan et al., 2012). However, and gain support, place pressure on local governments local ownership of both the technology development to change policy, and enhance enforcement practices and the treatment system used is an essential element in order to support larger scale basin management of its success. Demand-driven water treatment planning (Palaniappan et al., 2010). systems are far more sustainable than those which are

Figure 4.6: Map of Volta basin

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4.5 River Basin 4 – Chao Phraya The Chao Phraya River is considered the lifeblood of Thailand. The river supports 13 million people and is used in a variety of ways, including for drinking water, irrigation, and as the primary water source for the Tha Chin River. Under low to average water conditions, domestic, agricultural, and industrial discharges are greater than the river’s capacity for self-purification. The main source of water pollution is untreated wastewater from domestic sources. Existing wastewater treatment plants service only limited areas. Therefore, the construction ofnew wastewater treatment plants is suggested in order to improve water quality. Moreover, community involvement, through means such as water conservation and waste minimisation programs in Pathum Thani and Nonthaburi, are essential to the success of water quality programmes.

4.5.1 Brief overview of Chao Phraya Basin km2. Similarly, the upper Ping River Basin also consists characteristics and governance of areas with a highly concentrated population. The Chao Phraya River basin is located between latitude Increasing human settlement and changes in land 12 01’ to 19 45’N and longitude 98 10’ to 101 30’E. It cover have caused degradation of water quality, covers ca. 160,000 km2, representing 30 per cent of the increased frequency of flash floods, erosion and country’s total area, and 57 per cent of its population. landslides. The upper region of Chao Phraya basin is mountainous Various agencies are responsible for water governance with agriculturally productive valleys and the lower in the Chao Phraya River basin. The Electricity region contains alluvial plains that are highly productive Generating Authority, Thailand (EGAT) controls the for agriculture. water release from the two main reservoirs in the basin The Chao Phraya River basin consists of the upper and the Royal Irrigation Department (RID) regularly four tributaries of Ping, Wang, Yom, and Nan; the monitors the water level at the lower reach of Chao lower two tributaries of Pasak and Sakae Krang; and Phraya at the Chainat diversion dam. The Pollution the delta of Chao Phraya and Tha Chin (Paramee, Control Department (PCD) monitors the water quality 2003). The region is dominated by the monsoon, of the Chao Phraya Delta. In the Thachin river basin, with a rainy season lasting from May to October and several environmental agencies and provincial and supplementary rain from occasional westward storm local governments have been developing policies and depressions originating in the Pacific. The annual action plans to manage and improve water quality. precipitation is 1,179 mm with an annual discharge 4.5.2 Typical water pollution problem, causes of 196 m3/s. There are two large dams in the Chao and impacts Phraya River basin: Bumiphol and Sirikit which control The lower reaches of Chao Phraya River basin are the runoff from 22 per cent of the basin. The whole considered to be the most polluted of the basin, and basin is rich in biodiversity and contains extensive the Tha Chin River one of the most polluted rivers areas of rainforest. The lower part of the basin has in Thailand. According to the routine water quality extensive irrigation networks, enhancing intensive rice monitoring by the PCD, the lower reaches of Chao paddy cultivation. However, in recent years, human Phraya and Tha Chin have not met National Surface intervention has been increasing in forest areas Water Quality Standards since the 1990s. Based on the resulting in the conversion of forest to agricultural 2009 Annual Report on Water Quality Management by land. PCD, the overall water quality in Thailand has declined About half of the population of the Chao Phraya significantly during the past 10 years. According to the River basin is living in the Bangkok Metropolitan 2009–2013 water quality index (WQI) data, Bangkok Area (BMA) and parts of Samut Prakan, Nonthaburi (the Chao Phraya River) has the poorest water quality and Pathumthani. Bangkok and its vicinity has the as shown in Figure 4.8. highest population density with 1,497 inhabitants/

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Figure 4.7: Map of Chao Phraya basin.

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Deteriorated

Figure 4.8: Trends of water quality in the Chao Phraya and Tha chin Rivers from 2009 to 2013 (PCD, 2013).

The concentrations of selected water quality parameters which threatens many species of aquatic life. Similarly, in the Upper, Central, and Lower Chao Phraya River and water quality in the Tha Chin River is heavily degraded, Tha Chin River for the year 2013 illustrate this gradient due to the combined discharges of industrial, domestic (Table C.1, Annex C). The parameters indicating poor and rural effluents. water quality in the dry season are faecal and total In general, the basin is entering a critical period in which coliform bacteria (FC and TC), NH -N, and BOD, whereas 3 small changes in hydrologic conditions can create large those in the rainy season are FC, TC, and NH -N. 3 socio-economic disturbances. In recent years, land use Municipal waste and industrial effluents result in low in the Chao Phraya and Tha Chin River basins has been DO levels and high BOD levels in the lower Chao Phraya changing from agricultural to urban and industrial. Due and Tha Chin River basins. Industrial wastes contribute to the increase in population, it is unavoidable that to low DO levels below the water quality standard new settlements will be built in areas where water (Kunacheva et al., 2011). The surrounding agricultural management is difficult. Human impact on water areas also contribute to a high amount of NH -N and 3 resources, and vice versa, is visible throughout the basin. derivatives in the basins. The levels of TC and FC, which Native plants acting as surface cover on native land are reflect the sanitary quality of the river, are degrading being destroyed at a rapid pace, causing flash floods, because of the discharge of human and animal wastes erosion, and landslides. The construction of dams and into the river (Campos & Cachola, 2007). diversions requires the resettlement of people, usually The major issues of water quality are low levels of DO, to unclaimed and infertile areas. In the lower part of frequently below 3 mg/l, high organic matter (BOD), and the basin where intensive irrigation networks exist, rice high FC (Simachaya 2003). Land-based BOD loading into is cultivated year-round. Thirty years ago, the same the Upper Gulf of Thailand has increased from 207 t/ area had a single annual rice harvest. Since then, the day in the 1990s to 1144 t/day in the 2000s (PCD, 1997). number has doubled, then tripled, and today there is Total nitrogen loading from the Delta, Chao Phraya and continuous cultivation. Clearly, the land is heavily used, Tha Chin River contributes up to 116,000 t/yr to the with no time for revitalisation. Upper Gulf of Thailand (Leelapanang, 2010). As a result, 4.5.3 Solutions and transferable lessons the estuary in the Upper Gulf of Thailand has frequently experienced algal blooms; red tides occurred 18 times The National Policy regarding water quality is stipulated at the river mouth during the year 2008 (MCRC, 2009). in both the National Economic and Social Development The Chao Phraya River exhibits serious organic pollution Plan and in the National Policy and Plan for Natural

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Resources and Environment Management, which Generating Authority of Thailand) and RID (Royal set long-term (twenty-year) goals, standards and Irrigation Department) can to some extent improve strategies. In the Eighth Plan, the national goal was to the poor downstream water quality during the dry maintain the quality of surface water at the 1996 level season. Allocation of basin water supplies must take (UNESCO, 2003). into account these needs (Pattanee, 2005). The maintenance of river integrity is based on Thailand has developed master plans of water quality maintaining minimum stream discharges to repel management for major river basins including the Chao salt-water intrusion in the lower reaches of rivers, Phraya. Construction of wastewater treatment facilities dilute pollutants and maintain minimum dissolved in municipalities is prioritised and recommended as oxygen levels to ensure that the quality of the aquatic well as a control of wastewater from industrial and environment does not fall below acceptable levels. agricultural sources. The government has “mobile land A minimum flow of 16 m3/s is currently considered doctor units” helping farmers to diagnose and remedy sufficient in the lower reaches of the Chao Phraya River land degradation problems. Charging fees for waste to repel salinity intrusion. Pollution control is more discharges is also being studied and will be applied to problematic. Most of the wastewater discharges of many sites in the near future. Four municipalities apply domestic and industrial origin have increasingly been the Polluter-Pays-Principle for wastewater treatment controlled and mitigated through the enforcement plants and a few more are working towards this policy. of separate effluent standards by various regulating Water quality models and geographic information governmental agencies. In addition, the regulation of system (GIS) have also been developed and used as tools streamflow in the Chao Phraya River by releases from to help decision-makers in water quality management upstream reservoirs operated by EGAT (Electricity (Pattanee, 2005).

4.6 River Basin 5 – Setting resource quality objectives for the Vaal River

The Vaal River drains what is effectively the economic hub of Africa, the city of Johannesburg in South Africa. This city was built in the late 1800s and 1900s as a mining city and has innumerable mines dotted around the city, with thousands of kilometres of tunnels beneath the city streets. As mines have been depleted and closed across the Upper Vaal basin, groundwater has risen bringing with it toxic acid mine water which decants onto the surface and into the rivers. Operational mines also pump to void mine water, which also enters the surface water resource. Despite many initiatives to mitigate this issue, even by treatment of the mine water and an active programme to dilute the salinity using inter-basin transfers of cleaner water, the net result is a salinity problem in the rivers downstream. Recent management interventions include the setting of Resource Quality Objectives (RQOs) for the river downstream that are codified in law and become objectives for management action. This study provides an example of how water quality monitoring can be translated into management objectives.

4.6.1 Brief overview of Vaal Basin characteristics 197,000 km2 providing habitation for some 5.6 million and governance people. Water resources in the area have been fully The Vaal River runs through four of South Africa’s allocated for over three decades, and 54 per cent provinces (Gauteng, Free State, North West, and of water requirements are met through inter-basin Mpumalanga), and eventually joins the Orange transfer schemes primarily from Lesotho via the River which runs into the Atlantic Ocean. This water Lesotho Highlands Water Project, and the Thukela management area is of major national strategic and catchment. Owing to such interdependencies between economic importance because it hosts economic catchments, water infrastructure (numerous dams and activity amounting to 20 per cent of South Africa’s inter-basin transfer schemes) is considerable and its Gross Domestic Product. It has a catchment area of management is increasingly key to water supply.

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4.6.2 Salinity pollution in the Vaal River, causes levels off at approximately 600 mg/l due to the dilution and impacts management rule practiced in the Vaal Barrage, where Poor water quality of surface and groundwater water from the upstream Vaal Dam is used to dilute resources is a major issue in the Upper Vaal, both and manage the salinity. through direct impacts from mining and industry 4.6.3 Solutions and transferable lessons (return flows from mine dewatering) and indirectly The Water Act of 1998 (of South Africa) requires that from air pollution (coal power stations). The Vaal River Resource Quality Objectives (RQOs) be set for all water Reconciliation study (DWAF, 2009b) identified that resources in South Africa, including rivers, wetlands, salinity (as represented by Total Dissolved Solids, TDS), estuaries, lakes, and groundwater and a procedure eutrophication and microbiological water quality are was drafted to regulate this process (DWA, 2011). The the major water quality issues in the river. selection of objectives takes into consideration both, Levels of salinity, as indicated by TDS concentration, the quantity and quality of water resources, as well are shown in Figure 4.9. The impact of effluent as the habitats and biota associated with these water discharges and diffuse sources in the Vaal Barrage resources. The objectives are selected after the water catchment is apparent from the substantial increase in body is assigned a “management class”; this class is TDS concentration between Vaal Dam (VS7) and Vaal based on the socio-economic and ecological drivers Barrage (VS8), where the TDS concentration is 7.3 times and requirements of the water resource (DWA, 2012). greater than natural concentrations (DWAF, 2009a). During 2014, the RQO procedure was implemented The increase in the TDS concentrations from the for the Vaal River, but only the Upper Vaal is described point VS7 to VS8 is attributable to the highly saline here. tributaries that drain into the Vaal Barrage but also The main steps for determining RQOs are: includes diffuse pollution (DWAF 2009a). The Vaal 1. Delineate resource units (RUs). Barrage sub-catchment is one of the most complex 2. Prioritise thoseesource r units that have water catchments in South Africa. It is highly developed “issues” (see Figure 4.10). with industries, urban areas and mining activities. In 3. Prioritise those components that would best excess of 90 per cent of the dry weather flow is made illustrate these “issues”. Components should up of return flow emanating from the respective include quantity, quality, habitat and/or biota. tributaries. The TDS concentration in the Vaal River

Figure 4.9: TDS concentrations (mg/l) in the Vaal River showing the th5 , 25th, 75th and 95th TDS concentration percentiles (figure redrawn from DWAF 2008).

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Figure 4.10: Prioritised Resource Units for the Upper Vaal catchment demonstrating the extent of coverage of the legally binding Resource Quality Objectives (DWS, 2014). RQOs are set for each of the indicated Resource Units.

For example, in some areas nutrients may be the Key features of these RQOs are: driving issue, in others an indicator fish species • The RQOs respond to the classification of the may be the best indicator of what is happening water management area (basin) into management with the resource, etc. classes which addresses both biophysical and 4. Determine RQOs for each resource unit that socioeconomic needs and influences. would serve to maintain the water resource • The RQOs are generally narrative as this (quantity, quality, habitat and biota) in a condition allows greater certainty and concordance with that meets the desired Management Class. A stakeholder requirements. key characteristic of the RQO procedure is that • The RQOs are supported by numerical limits which the RQOs themselves are essentially narrative may be subject to improvement as information and describe the objective in terms that can and data is added following both monitoring and be accepted by stakeholders. These are then also developments in understanding. supported by Numerical Limits which are subject The RQOs and the numerical limits are gazetted in the to change as knowledge and science improves. Government Gazette and thus become legally binding This procedure was implemented for the Upper Vaal on all authorities. The Department of Water and (DWS, 2014). While this report documents all of the Sanitation is required to control sources of pollution many issues and the resulting RQOs for the quantity, and impact so that the RQOs can be met. It does this quality, habitat, and biota for the Upper Vaal (Table through a system of Source Directed Controls (licenses). C.2, Appendix C), only selected salinity results are illustrated here.

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4.7 River Basin 6 – Medjerda

The Medjerda river basin is the only permanent stream in Tunisia. It originates in the Atlas Mountains of eastern Algeria, crosses Tunisia’s Northern region and discharges into the Golf of Utica in the Mediterranean Sea. The continuous increase of pressures on water use in the region for agriculture, industry and urbanisation deteriorate the in-stream and nearshore water quality of the Medjerda significantly. A strategy for joint soil and water conservation measures is needed to identify hot spot and vulnerable areas to reduce sediment loads and their associated impacts. Participative actions for awareness-raising are especially targeting “the new generation” and local population.

4.7.1 Brief overview of Medjerda Basin silting of its reservoir. Zahar et al. (2008) reported that characteristics and governance the Sidi Salem reservoir has substantially reduced the The Medjerda River has an average discharge of 1 billion discharge of the Medjerda, altering the morphology m3/yr representing 37 per cent of the total surface of its cross section, but also reducing the frequency water of Tunisia and 22 per cent of the renewable water of floods at the downstream part. However, the resources in the country; it provides drinking water, impact of climate change in the region is thought to completely or partially, to 60 per cent of the Tunisian have increased the complexity of flood management. population (Jaouadi et al., 2012). The length of the main Although new guidelines for flood protection have river basin is about 484 km covering an area of 23,700 been adopted for the management of the Sidi Salem reservoir, the frequency of flooding remains high and km2, 32 per cent of which is located in Algeria (Figure perhaps is even increasing, as indicated by high water 4.11). Mean precipitation in the Medjerda river basin events in 2003, 2004, 2005, 2012, and 2015. ranges from 600–1,000 mm/yr in the north sub-humid region to 300–400 mm/yr in the south semi-arid to Water monitoring in the basin is provided mainly by arid part of the basin, resulting in an average of about two agencies: the “Direction Générale des ressources 480 mm/yr. The main economic activity in the basin is en Eau” (DGRE) for water resources and the Agence agriculture which produces a large fraction of the total Nationale de Protection de l’Environnement” (ANPE) national cereal production (70 per cent of the cultivated for water quality. area). This gives the basin a central role in national food 4.7.2 Typical water pollution problem, causes security. As a result, most of the available water in the and impacts Medjerda catchment is used for irrigation (80 per cent). Jdid et al. (1999) have reported that water quality Meanwhile, the household and tourist sectors account in the north-western part of the Medjerda basin is for 16 per cent of water use, and industry 4 per cent. characterised by high heavy metal concentrations, Several wastewater treatment plants have been serving especially arsenic and zinc. The concentration of total municipalities near the river since 1994. dissolved solids (TDS) of surface water is in the range A large dam was constructed in 1981 on the main river of 0.14–4.2 g/l in most parts of the catchment, except tributary of the Medjerda following the severe flood the southwestern part (the Mellègue sub-catchment). of 1973 which saw river discharge reach 3,500 m3/s. Here TDS concentrations reach up to 9.68 g/l during Although the main goal of the Sidi Salem dam is to the dry season. Also, an analysis of physico-chemical provide flood protection to downstream inhabitants and bacteriological parameters revealed degradation and agricultural areas, it also makes more irrigation of water quality: Faecal coliform bacteria reach a water available to the northern and central parts of the concentration of 1,100 cfu/100 ml below the largest country. In addition, electricity is produced at several cities (such as Jendouba and Beja, Figure 4.11). Also, hydropower plants using water stored behind the dam. at some stations nitrogen and phosphorus loads reach Even though the Sidi Salem reservoir has contributed values of 330 and 315 kg/day, respectively. From the to the development of the Northern regions (for ecological perspective, measurements of the free- example, by providing water for expanding irrigated flowing part of the river (Riahi & Ben Thayer, 2008) areas), it has also had significant adverse impacts on and the Sidi Salem reservoir (Koumaiti et al. 2010) the natural environment, especially related to the indicate that the river is mesotrophic.

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Figure 4.11: The geographical location of the Medjerda catchment and its digital elevation model.

High heavy metal concentrations are caused by Agriculture is suspected of being the largest leaching from closed mining activities and by the contributor to non-point source pollution. However, intrinsic geochemistry of the sub-soil, which has high its contributions have not been quantified because of natural concentrations of heavy metals. Bouraoui the lack of monitoring of in-stream water quality. Also, et al. (2005) have reported that the Medjerda River food industries produce large volumes of wastewater basin is experiencing an intensification of agriculture containing high levels of organic pollutants, which and irrigated area is increasing rapidly. In addition to affect the aquatic ecosystem of the Medjerda diffuse sources, point sources (e.g., sewage plants) River. Even though many industries have their have significantly increased during the last decade. It proper wastewater pre-treatment plant, the lack of is estimated that the Medjerda River basin receives maintenance and experienced staff to run these plants 1.27 million m3/yr of untreated and 12 million m3/ means that they do not always operate effectively. yr of treated wastewater from the sewage systems An additional threat to the water quality of the river (DGRE, 2006). The increased use of fertilisers in comes from the possible leaching of lead, zinc and agriculture during the last decade has also affected other compounds from mine tailings at abandoned shallow aquifers, where nitrate concentrations reach mining sites especially in the north-western part of about 300 mg/l near irrigated areas. The catchment the basin (Mlayah et al. 2009). is also subject to soil erosion episodes due to heavy Accelerated soil erosion occurred during the last rainfall events characteristic of the Mediterranean decade due to the increased frequency of flooding region. Moreover, it was found that the most severe and led to siltation in the river. Economic impacts soil erosion episodes occurred particularly at the occurred because of losses in soil productivity due beginning of the rainy period (September-October) to decreases in fertile soil volume, losses of nutrients after a long dry period (hot summer) following the and organic matter, the need for greater quantities crop harvesting and soil tillage season (Mosbahi et al., of fertilisers to make up for diminished soil fertility 2013). as well as the reduction in the life span of dams and reservoir capacities. Environmental impacts arise from

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the siltation and increased turbidity of waterways. The dams in the Medjerda basin are threatened Environmental impacts are not always restricted to by siltation. Thus, a strategy for soil and water those regions where erosion occurs; high levels of conservation measures is needed to identify hot spot nutrients, associated with erosion of agricultural soils, and vulnerable areas to reduce sediment loads and may be transported to the mouth of the Medjerda their associated impacts. Also, for better water quality River and contribute to coastal eutrophication and assessment in the Medjerda catchment, an innovative possibly hypoxic conditions. high resolution monitoring approach is recommended 4.7.3 Solutions and transferable lessons for the future. In order to protect the limited resources in the Recently, action has been taken in Tunisia to increase Medjerda catchment, various Tunisian agencies are public awareness for water resources management working together on an ambitious sustainability and environmental preservation. The association project. For this, an interdisciplinary framework was “Research in Action” (REACT) encourages sustainable established covering environmental, socio-economical development by encouraging an easier transfer and institutional aspects. of scientific results related to water resources Faced with ever-increasing challenges of water management and environmental preservation to resource management in the country, a coherent different target groups. REACT has aimed to raise national water policy is essential. In Tunisia, soils are awareness about water issues among the youth of the under serious risk due to long dry periods followed country through lectures, videos and events focused by heavy bursts of intensive rainfall, falling on steep on sustainable water management, and games related slopes with fragile soils and low vegetation cover. to water sharing.

4.8 River Basin 7 – Elbe

The transboundary Elbe River basin is under pressure from point and diffuse sources that cause increased concentrations of nutrients and other water pollutants. Although nitrogen and phosphorus loads havebeen steadily decreasing, further measures are needed to achieve a range of environmental objectives. Catchment wide management options are planned in the Elbe River Basin Community, which is an association of ten German federal states.

4.8.1 Brief overview of Elbe characteristics and the dry-continental climate of Central and East Europe. governance Average annual rainfall varies from less than 500 The Elbe River has its source in Krkonoše Mountains mm in the regions of Thuringia and Saxony-Anhalt to in the Czech Republic and discharges after more than 1,800 mm in the Harz Mountains. The catchment wide 1,000 km into the North Sea via an estuary that widens average rainfall is 628 mm, which is balanced by an up to 15 km. Two-thirds of the catchment area of average annual evaporation of 445 mm. Typically, the around 150,000 km² are part of Germany. One-third discharge into the Elbe River is high in late winter and of the catchment is part of the Czech Republic. Minor spring due to snow storage and snow melt. However, areas belong to Austria and Poland. Main confluents are infrequent flooding may also occur in summer. The the Vltava in the Czech Republic and the Saale as well average annual discharge at the German-Czech border the Spree/Havel system in Germany (Figure 4.12). This is 311 m³/s which increases at the catchment outlet to case study will mainly focus on the water management 861 m³/s. Approximately 60 per cent of the German issues in the German part of the catchment. Within catchment is used for agriculture, nearly 30 per cent is Germany, ten federal states cover areas of between 0.9 forest land and less than 10 per cent is covered with per cent (Berlin) and 24.4 per cent (Brandenburg) of the settlements. The transboundary catchment has about catchment area. 25 million inhabitants, 75 per cent of them live in the German part. In addition to Berlin and Hamburg, major The catchment is characterised by a transitional climate cities are Leipzig and Dresden (Figure 4.12). from the humid-oceanic climate of Western Europe to

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Figure 4.12: Topography of the Elbe River Basin, with its major cities, and the main tributaries of the river.

In 1990, an International Commission for the 4.8.2 Typical water pollution problems, causes Protection of the Elbe River was founded. The main and impacts objectives of this transboundary organisation are In the German part of the Elbe River basin five to promote the fair use of river water, especially for important management issues are discussed from a municipal users via river bank water extraction and for catchment wide perspective agricultural water users, while maintaining the health • Hydromorphological deterioration and of its aquatic and riparian ecosystems and healthy flora longitudinal continuity and fauna. The Commission also aims to develop a • Contamination with pollutants and nutrients strategy to decrease the burden imposed on the North Sea ecosystem by the Elbe River basin (IKSE, 1990). • Sustainable management of water quantity Germany, one of the main riparian nations of the • Local impact of mining activities Elbe, has established the Elbe River Basin Community • Adaption to climate change. for managing the part of the river basin that crosses Recent activities mainly focus on the enhancement of German state borders. Members of the Community hydromorphological conditions and the improvement are the federal government and the ten federal of fish migration as well as the reduction of states which share a part of the catchment. The contamination by pollutants and nutrients. The Community mainly focuses on the implementation of latter is also important because of side effects on the European Water Framework Directive (WFD) and coastal and marine water bodies. With respect to the Floods Directive (FD) (FGG Elbe, 2009). With the marine environment protection, a total nitrogen (TN) exception of Berlin and Hamburg, water management concentration limit of 2.8 mg/l has been defined administration in the German states is hierarchically for marine and coastal water bodies. This can be structured on two or three levels. Generally, the compared to a TN concentration of 3.4 mg/l averaged supreme authority is a state ministry. for the years 2009 to 2012 at the monitoring station

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Seemannshöft which is located at the catchment crops, reduction in intensity of farming practices, iii) outlet. The non-binding target value of total fertiliser management, iv) modification of land use phosphorus (TP) concentration for this monitoring including establishment of buffer strips or “living station is 0.1 mg/l, which is exceeded in samples by fences” v) tile drain management and vi) mentoring up to 100 per cent. Figure 4.13 illustrates the general and transfer of knowledge. In detail, these measures downward trend of TN and TP over a longer period are adapted to regional and local requirements. Point of time. The decrease of nutrient concentration values source management includes both the improvement is typical also for the vast majority of monitoring of wastewater treatment efficiency, and the stations in the German Elbe River basin, which shows management of urban stormwater runoff. a long term trend starting in the 1990s with an initially The effect of the measures is estimated on the one rapid decrease of nutrient concentrations. However, hand by expert judgment and on the other hand by a slowing of the decreasing trend can be observed in nutrient balance modelling and scenario calculations. recent years. And, compared to the average, the inter- The combination of these methods increases the annual variability is increasing. For TN, an influence reliability of assessments and planning. Nutrient of hydrological and meteorological conditions in the balance modelling with MONERIS 3.0 has identified winter period is considered to be the main trigger the main sources and pathways of nitrogen as: for the observed variations. Also intensification of groundwater and interflow (40 per cent), tile drains land use may have caused these changes. In 2013, (25 per cent) and waste water treatment (20 per 29 per cent of the groundwater bodies showed an cent). Tile drains are more important as pathways in unsatisfactory chemical status because of accelerated the northern lowland part of the catchment and urban nutrient concentrations. waste water prevails in cities e.g. of Berlin or Hamburg. Measurements in coastal water bodies show that For phosphorus, the main sources and pathways are: high nutrient concentrations cause chlorophyll groundwater and interflow (20–25 per cent), waste concentrations that are up to 400 per cent beyond water treatment (20–25 per cent), erosion (13 per the target value. Also in the Elbe River and main cent) and tile drains (10 per cent). Erosion is more tributaries, elevated concentrations of chlorophyll important in the southern part of the catchment due and corresponding oxygen concentration depressions to its relief. By expert judgment, a significant reduction are found. In the Elbe estuary, summer oxygen of nitrate input into surface and groundwater of 10- concentrations often are close to a critical value 15 per cent in the German part of the catchment because of nutrient enrichment and eutrophication. is expected because of the amendments of the Pressures on single water bodies or on micro/ Fertilisation Ordinance. Agri-environmental measures mesoscale catchments can be reduced on the local to control inputs from drains and improved efficiency level with consideration for specific management in waste water treatment have a high potential for demands. However, the nutrient concentrations and reduction of nitrogen loads. Wastewater treatment is loads in macro-scale catchments such as the Elbe also the main option for reducing phosphorus loads. River and the associated coastal and marine water Strategies are also developed for the other above- bodies can only be reduced by coordinated measures mentioned important management issues that to reduce emissions and to increase the retention of include a status description and options for measures. nutrients by all responsible upstream authorities. With These strategies are the basis for public discussions. the implementation of the WFD, the ten riparian states For example, a detailed plan was set up to improve have set up an approach which combines measures for fish migration in the main tributaries at 171 dams, point sources, diffuse sources and nutrient retention. locks and weirs up to 2021. A sediment management Additionally, synergies with measures to improve concept was compiled that sets up a framework for the structures, e.g., of habitats, are expected. Major evaluation and management of sediment and particle options to reduce the nutrient input from agricultural bound contaminants. Such contamination problems diffuse sources are i) amendment of the Fertilisation are often caused by emissions from contaminated Ordinance (Düngeverordnung, DÜV), ii) improvement sites but also by reworking of old sediment structures. of crop rotation including intertillage and undersown

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Figure 4.13: Long-term trends of nutrient (Ntot = total nitrogen TN, Ptot = total phosphorus TP) concentrations at the monitoring station Seemannshöft at the mouth of Elbe. Box-and-whisker plot: central bar =median; tops and bottoms of rectangles = 25th and 75th percentile; asterisks = minimum and maximum values.

4.8.3 Solutions and transferable lessons After a period with a significant decrease in nutrient The nutrient management problem under discussion loads, the rate of decrease has diminished in recent is at the intersection of different stakeholders years both for N and P, despite continuing mitigation and drivers, i.e. agriculture, water pricing, water measures. This may be caused by inertial effects authorities, and nature conservation, to name but a after the initial strong reduction of nutrient loads, few. However, the WFD, national laws and regulations, or because the measures are ineffective, or perhaps and other international conventions define the target because the positive impact of the measures is being frame. The consideration and acceptance of target delayed for unknown reasons. The situation in the Elbe values for nutrient reduction in coastal water bodies in River basin is comparable to that of other rivers with inland states is an important step in the achievement high concentrations of pollutants despite control of of objectives. Modelling results support the pollutant loadings to the river (Dorioz and Tadonléké identification of nutrient sources as well as pathways 2009). and a catchment-wide strategy that includes regional The administrative structure of the Elbe River Basin characteristics. Modelling also provides a basis for Community, which coordinates the efforts of the defining regional (inland) measures that focus on federal states in the German part of the Elbe River the effective reduction of nutrient input in coastal catchment, established the basis for an integrated water bodies. Local pressures are also included at a and coordinated plan of action. The Elbe River Basin small scale. On the negative side, modelling results Community works on the principles of voluntary and are sometimes not accepted in public discussions consensus decision making, and in this way reflects the about water pollution because models are difficult federal structure of Germany. The joint identification to understand, and because they sometimes lack of management problems at the catchment scale is adequate input data. The integration of expert the prerequisite for a common understanding and knowledge in the discussions can partly compensate defining environmental targets and management for these shortcomings. options.

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4.9 River Basin 8 – Hudson

The Hudson River basin is a typical example of a mixed-use watershed in the developed world. Historically, the trajectory of water quality issues has followed the transition from settlement, deforestation and resource extraction, through agricultural expansion, industrialisation, and urbanisation. Today, the dominant water quality issues reflect the local history of development and its regional variation.

4.9.1 Brief overview of Hudson Basin reservoir system (17 reservoirs, with watersheds characteristics and governance straddling the Hudson and Delaware basins) The Hudson River basin, including its major tributary, the supplies NY City and other cities of the region, and Mohawk River, is situated primarily in New York State, represents an interbasin transfer of water; with small portions lying in the neighbouring states of • Canal system: the New York State barge canal Connecticut, Massachusetts, New Jersey, and Vermont. system connects the river to the Great Lakes and There is a strong gradient of land use/land cover, with Lake Champlain, providing an opportunity for the northern Upper Hudson dominated by forest, the invasive aquatic species. Central Hudson/Mohawk by forest, agricultural and Invasives: The Hudson River exchanges biota with suburban lands, and the southernmost portion being neighbouring basins through canals and aqueducts. heavily urbanised. Two large park areas, the Adirondack Among these biota, Eurasian water chestnut (Trapa Park in the north and the Catskill Forest Preserve in the natans) and water milfoil (Myriophyllum spicatum) southwest, help protect a significant portion of the became established and invasive. In particular, watershed from development and associated potential thick water chestnut beds choke backwaters and water quality impacts. The New York City water supply embayments. In 1991, zebra mussel (Dreissena system provides drinking water for the New York City polymorpha), which had invaded the Great Lakes in the metropolitan area and other towns in the region, but 1980s via ship ballast, was discovered in the Hudson its catchment (within the Hudson and Delaware basins) River, most likely transported on boats. By 1992, zebra is protected from excessive development. mussels represented > 50 per cent of the heterotrophic Pollution: From the 1800s to the 1960s, the Hudson biomass (Strayer et al. 2014). River was grossly polluted by effluent from river cities Climate change: Effects are already evident in the and industry, but with programs such as the Pure Waters Hudson River watershed: sea level has risen ~30 cm Bond Act in 1965 and passage of the Clean Water Act in since 1940, freshwater discharges have increased, and 1972, funding became available for improved sewage temperatures have been rising since 1930 (Strayer treatment, ultimately resulting in the return of sensitive et al. 2014). Although phenological responses in indicator species in the 1990s. Today, while phosphorus organisms have been moderate, timing/duration of loading has diminished largely due to the removal of spawning runs of anadromous (sea-run) fishes has phosphorus from detergents, the Hudson still remains been changing, moving toward earlier runs that may the most heavily loaded US estuary in terms of nitrogen, not match up well with in-river primary and secondary the source of which varies from the forested north production. Regional climate projections indicate more (atmospheric deposition), through the agricultural concentrated precipitation events, including major centre (farm runoff) to the urban south (wastewater storms which result in severe flooding as in 2011 discharge). Hurricane Irene and Tropical Storm Lee and in 2012 Hudson River Facts Hurricane Sandy. • Hudson/Mohawk basin area: 34,680 km2; There is no single governance system for the watershed; • Hudson River length: 507 km from its primary a number of different agencies and programs from source in Lake Tear of the Clouds to the tip of federal to local hold responsibility for water quality Manhattan Island; regulation. The Hudson River Estuary Program (HREP), funded by New York State and managed by the state’s • Average precipitation: 1000–1275 mm/yr over a Department of Environmental Conservation (DEC), has significant north/south gradient; a watershed management programme in place to help • Major regional water supply system: the NYC mitigate impacts from urbanisation, development,

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Figure 4.13: Regional map showing the Hudson River watershed (yellow) and other major features of the region including the Delaware watershed (green), the five boroughs (counties) comprising New York city (hatched), the New York City water supply watersheds (red outline) and aqueduct/ tunnel system (purple). Counties of New York and surrounding states are outlined in grey. Inter-basin transfers occur through the Champlain and Erie Barge canals (dark blue).

agriculture, and climate change. The Estuary Program during maintenance dredging, volatilised off, or has an active stakeholder advisory board that helps to transported by the river downstream to the Atlantic, guide action plans. The New York City Department of significant portions remained in floodplain soils and Environmental Protection (DEP), a city-level agency, is river sediment, becoming bio-available and taken up responsible for monitoring and securing the integrity of in terrestrial, riverine and estuarine food chains. In the City’s water supply system, including its watershed, 1976, New York State banned all fishing from the and its sewage and waste treatment system. As most source region to the Federal Dam at Troy, NY, and closed of the City’s sewage is treated and discharged to the commercial fisheries for striped bass in the 250 km Hudson and other waters around Manhattan, the of tidal estuary downstream of Troy. Eight years of DEP also monitors water quality in the harbour and study later, the US Environmental Protection Agency nearby waters. Non-governmental organisations also (EPA) designated the entire stretch from Hudson Falls play a significant role in monitoring water quality and (320 km from the mouth) to New York Harbor as a pollution. Superfund site. Despite that, the complexity of the 4.9.2 PCBs: causes and impacts problem, compounded by a bitter battle between GE and the EPA, led to inaction for decades. In the In addition to the above concerns, the largest meantime, a consortium of academics and state single toxic contaminant issue in the freshwater agencies monitored the ecosystem, documenting the portion of the Hudson is that of polychlorinated bioaccumulation of persistent congeners and impacts biphenyls (PCBs). From 1946–1977, the General on fish and wildlife. Electric Corporation (GE) discharged hundreds of The primary impacts of the PCBs in the Hudson River tons of Arochlor, a mixture of PCB congeners used were unacceptable risks to human health and the in manufacturing electrical capacitors. Although a environment. Since the loadings have stopped, there portion of the discharged PCB mass was removed

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has been a very slow process of natural recovery of contaminated sediments from the upper Hudson the river ecosystem. Concentrations of PCBs in sport between the discharge points (in Fort Edward and fish and in fish commonly taken by the commercial Hudson Falls) and the Mohawk River confluence at fishery exceeded both the tolerances set by the the head of the estuary. This dredging and removal United States Food and Drug Administration (FDA) began in 2009 and was completed in 2015. and the concentrations used by the New York State While EPA was assessing what was necessary to Department of Health (DOH) in advising the public on support development of the remedial dredging consumption of wildlife. As a result, the State of New program, the State of New York, the US Department York banned the taking of fish from the 70 km reach of the Interior (DOI) and the National Oceanographic between Hudson Falls and the estuary (referred to in and Atmospheric Administration (NOAA), acting as project documents as the “upper Hudson”), closed Trustees of natural resources, conducted assessments the commercial fishery, and issued an “eat none” of potential injuries to a variety of these natural advisory for the entire Hudson River from Hudson Falls resources. These assessments include measuring downstream to the mouth of the river at the Battery in impacts of PCBs in the Hudson River ecosystem on New York. American mink (severe reproductive impairment), birds Following a halt in discharges in 1977, PCBs in water such as tree swallows (growth and development; and fish dropped fairly quickly, but levels stabilised in nesting behaviour), and shortnose and Atlantic many species by the mid-1980s, particularly in the sturgeon (survival; growth and development). This upper Hudson. PCB concentrations in most species assessment work is ongoing remained well above the FDA tolerance and/or the 4.9.3 Solution(s) and transferable lessons DOH consumption advisory guidelines. At the request EPA’s selection of targeted environmental dredging of the DEC in 1989, EPA began a major reassessment was intended to accelerate the natural recovery rate of conditions in the Hudson related to GE’s PCB of the river ecosystem. EPA concluded in the Record discharges, including extensive monitoring of PCBs of Decision that two active remedial approaches in the water column at different flows and times of would be necessary to promote this: control of the year, sampling of known PCB “hot spots” (areas ongoing sources and removal of the most highly mapped by DEC as containing deposits of concentrated contaminated portions of the river bottom (including sediment-bound PCBs in discrete locations) to look the “hot spots”) which acted as ongoing sources to at changes over time, and annual monitoring of fish the rest of the river system. Source control at the two at various trophic levels in several locations river capacitor plant sites was achieved before the start of wide. EPA also developed a set of predictive tools to the dredging project in 2009 through implementing a inform decisions about various remedial alternatives series of remedial actions by GE under State regulatory and conducted quantitative human health and authority. Actions undertaken at these sites included environmental risk assessments. Human health risks removal of contaminated sediments near major identified included both excess cancer risk and wastewater outfalls at the sites and groundwater and risk of non-cancer health hazards associated with PCB oil recovery programs designed to limit offsite consumption of contaminated fish. Ecological risks contaminant migration to the river. identified by EPA included population-level effects The most significant problems to address in the on piscivorous wildlife, including bald eagle, belted river were risks to people who consume fish and kingfisher, great blue heron, mink, and river otter. piscivorous wildlife. To reduce these risks, the PCB Piscivorous mammals were at greatest risk. body burdens of Hudson River fishes needed to EPA’s assessment of river conditions in their 2001 be reduced. Through geochemical evaluations and Record of Decision (U.S. EPA, 2001) concluded that modelling, EPA determined that fish received their trends in PCB concentrations in the water column PCB body burdens from both the water column and and fish tissue showed a levelling off with little if the food web, from PCBs in surficial and near-surface any reduction in the last decade. In the Record of sediments. To address these pathways, EPA decided Decision, EPA, following the process set in the Federal to remove the most highly contaminated sediments “Superfund” law, ruled that GE should conduct from areas where significant PCB mass was present targeted environmental dredging to remove the highly and potentially bioavailable or where significantly

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elevated PCB concentrations occurred at or near the necessary infrastructure was developed for the project sediment surface. PCB congeners containing three (sediment dewatering and transfer facility, work or more chlorines (“tri plus PCBs”) were targeted marinas), the contractor hired by GE performed the due to their greater propensity for bioaccumulation, first year of sediment removal. This first year (“Phase environmental persistence, and potential impacts on 1”) was planned to be an opportunity for both EPA human health and ecological risk. and GE to better understand project operations in the Removing targeted sediments and controlling context of meeting the three performance standards remaining upstream sources of PCB at GE capacitor and also in improving the quality of project operations. plants in Hudson Falls and Fort Edward is expected Difficulties encountered during Phase 1 included to reduce PCB concentrations in surficial sediments resuspension of PCBs due to several technical issues and thus reduce PCB body burden in fish, ultimately (e.g. need for repeated dredge passes to meet the decreasing human health risks posed by consuming residuals standard, inefficiencies in loading/unloading contaminated fish and ecological risks posed by fish of scows causing delays, presence of debris preventing consumption by wildlife. (The routes of exposure to bucket closures, etc.) and underestimating the areas humans and wildlife via floodplain soils will not be required to be capped due to underestimation of abated by the river bottom sediment remediation. To contaminant depth. After the first year of dredging, address the ecological and human health risks posed a peer-review panel of national experts in remedial by disposal of PCBs to the Hudson River, a robust dredging was convened to evaluate the project and investigatory and remedial program, potentially provide recommendations on project revisions, approaching the scale of the sediment remedy, may including revisions to the three performance be required.) standards. To determine specifically where to remove During Phase 2, the project has been successful in contaminated sediment, a sediment sampling and meeting resuspension standards; the drinking water analysis programme was undertaken. After using standard has been consistently met downstream of side-scan sonar to map the river bottom by surficial dredging operations, and the rate of PCB losses has sediment type, a core sampling programme of been < 1 per cent of the PCB mass dredged. Sediment approximately 8,000 cores, on a triangular grid of removal has significantly increased, with the annual 24 m spacing, was undertaken to map the distribution production rate exceeding goals in every year of Phase of PCBs in river sediments. 2 until 2015. The capping rate has also been low, with EPA also set three primary “performance standards”, less than 8 per cent of dredged areas being capped for resuspension (impacts on the water column caused due to inability to meet the residuals standard. by contaminant release during dredging), residuals The primary lesson learned from the dredging (the ability of the contractor to meet the project programme in the upper Hudson is that a large remedial cleanup concentration where dredging was done) dredging project can be successfully performed with and productivity (the rate of sediment removal on a low resuspension losses, even without controls such monthly and annual basis). The resuspension standard as silt curtains or sheet piles, assuming accurate was set at the drinking water standard for total PCBs characterisation of site conditions (especially depth of 500 ng/l (http://www.epa.gov/safewater/pdfs/ of contamination), a sufficiently conservative design factsheets/soc/tech/pcbs.pdf). The residuals standard approach in setting depth of cut which limits the need was set at 1.5 mg/kg tri plus PCBs. for multiple dredging attempts, and properly operated Once GE’s project design team completed the process dredge equipment, selected to match site conditions. of delineating the sediments to be removed, and the

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4.10 General conclusions from problems also persist in developed countries. It is clear that major efforts are needed to achieve sufficient the case studies water quality and the ecosystem services it provides.

Common problems occur around the world Similar problems can have different The analysis in Chapter 3 identified the scale of water immediate causes quality challenges in Latin America, Africa, and Asia While above it was shown that similar water quality from a “top down” perspective. In this chapter, water problems occur at very different places around the quality situations were reviewed in eight case studies world, the case studies also showed that similar of river basins from around the world that illustrated problems can sometimes have different immediate in a practical way the realities of these challenges. causes: The global analysis in Chapter 3 identified that about • A principal cause of the pathogen pollution in the one-third of all river stretches in Latin America, Africa, Chao Phraya River is the discharge of domestic and Asia have severe pathogenic pollution. Two rivers wastewater from sewers, whereas in the Volta in two different locations in the world – the Volta basin, the main source is not sewers but runoff in West Africa and the Chao Phraya in Thailand – from inadequate sanitation facilities. are different in character, but both have high levels • The salinity pollution in the Medjerda River is of pathogen pollution linked to the occurrence of caused largely by return flows from irrigation waterborne diseases. whereas in the Vaal River it is mainly from About one-seventh of all river stretches on the three wastewater from industrial sources and runoff continents were identified to have severe organic from mining activity. pollution. The Upper Tietê River in Brazil and the Godavari River in India are both affected by organic A range of underlying drivers, some pollution with high BOD loadings, high BOD river common, some specific concentrations, and frequent episodes of very low dissolved oxygen. Large stretches of both rivers have The case studies also illustrated that the immediate few fish and very low diversity. causes of water quality degradation, such as untreated wastewater discharges, are in turn driven by many Tens of thousands of river kilometres on each of different underlying factors, which may vary from river the three continents have severe levels of salinity basin to river basin: pollution. The Vaal River in South Africa and the Medjerda River in Tunisia are both examples for • Important underlying drivers of the water severe salinity pollution. High levels of salinity impede pollution of the Upper Tietê, Godavari, and the use of the river for water supply, irrigation water Chao Phraya, are urbanisation and economic and industrial use. activity which lead to discharges of concentrated, untreated wastewater. The Elbe is an example of a river that has overcome its earlier problems with pathogen and organic • For the Vaal, the main driver is also economic pollution but now confronts another type of water activity, especially industrial production. As noted quality challenge – high loads of nutrients that lead above, this leads to the discharge of untreated to eutrophication in its estuary reaches. The Hudson wastewater and runoff from mining activities. has also mastered its earlier problems with pathogen • For the Volta, the drivers are population growth and organic pollution while continuing to have high and inadequate sanitation facilities. At the onset nitrogen loads, but now suffers from the legacy of of the rainy season, there is a large wash-off of toxic pollution related to sediment deposits of PCB pollution from inadequate sanitation facilities which have found their way into the aquatic food web. from the land into the river. As can be seen from these examples, similar water • The water pollution of theMedjerda and the Elbe quality challenges are occurring around the world share a common driver: the demand for food. even if the locations and situations are very different. This demand stimulates the irrigation of cropland Developing countries are experiencing problems in the Medjerda basin and this in turn leads to that developed countries have overcome, but new irrigation return flows to the river containing salts

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and nutrients. In the Elbe basin, food demand some circumstances, to first manage the land. In is satisfied mostly by rainfed crops, which are the case of the Medjerda, management of run- applied with excess amounts of fertilisers, some off from agriculture is key to reducing salinity of which are washed off into the Elbe river. loadings to the river. In the case of the Elbe, an • For the Hudson River, the driver of its current ambitious basin-wide programme is successfully PCB pollution has been the demand for industrial intervening in agriculture in the basin to reduce products, which may contain dangerous materials nutrient wash-off from agricultural land. that are unsafely disposed of. Another driver • In cases where water quality problems are of water quality changes in the Hudson River is worsening, sometimes a first important step is to climate change, which has raised the level of the educate the public about the situation. This was sea at the river’s mouth, increased freshwater the successful approach used in the Medjerda runoff, and raised river temperatures, all with and Upper Tietê basins. potential ecological consequences. • Another effective tool to promote water quality management are basin-wide action plans and Coping with the water quality challenge targets as in the case of the cleanup programme of Finally, many valuable lessons about how to cope with the Upper Tietê, the Resource Quality Objectives the water quality challenge can be derived from the used in the Vaal basin, and the water quality case studies: master plans developed for the Chao Phraya • As seen in the Godavari, it is important to avoid basin. fragmentation of authority as this affects the • The Volta basin also shows that actions to control management of river water quality. water pollution require the strengthening of the • As seen in the Elbe and Volta, consolidating technical capacity for water quality management authority in an overarching international in the basin. “commission” can provide an indispensable The case studies also show that the challenge of instrument to deal with international aspects of protecting water quality is closely link with other water quality management. In the case of the Elbe, important goals of society – providing food, developing it was also shown that a wide-reaching national the economy, providing safe sanitation. Therefore, institution (the Elbe River Basin Community) can over the coming years it will be very important to link also provide a valuable platform for gaining the goals for water quality with other goals of the Post cooperation of all critical actors within a river 2015 Agenda and the new Sustainable Development basin. Goals. This topic is taken up again in Chapter 5. • As seen in the Medjerda and the Elbe, in order to manage water quality, it is essential, under

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5 Solutions to the Water Quality Challenge: A Preliminary Review

Aim of this chapter • To review technical and management options available as solutions to the global water quality challenge. • To give examples about the practical implementation of solutions. Main messages • There are many options available to developing countries for avoiding the water quality deterioration of their rivers and lakes. Among the main technical options are: (i) pollution prevention, (ii) treatment of polluted water, (iii) the safe use of wastewater and (iv) the restoration and protection of ecosystems. • Apart from established strategies, there are innovative new ideas which were not available or used by developed countries when confronted with similarly deteriorating water quality decades ago. Examples are: pollution prevention in industry, constructed wetlands, and conservation and maintenance of forested headwaters. • A “one size fits all” option will not work to solve the global water quality challenge. Instead, regionally adapted clusters of measures will be needed to control the diverse types of water pollution and sources of pollution. Some of these packages might be applicable to many different river basins.

Previous chapters have shown that water pollution is Now, as noted above, several countries in Latin prevalent and increasing in rivers in many countries America, Africa and Asia are following a similar trend. in Latin America, Africa, and Asia. The situation is Yet the majority of river stretches on these continents not completely different from what prevailed several are still in good condition and countries still have decades ago in North America and Europe when the chance to avoid further pollution and restore increasing population and economic activity propelled already-polluted rivers. The case studies in Chapter 4 a substantial increase in water pollution. At that give some examples about how this can be put into time, the accent was on economic development at practice through various management approaches and the expense of environmental quality. After several technical options (Table 5.1). As we see later, these decades, the intensity of water pollution peaked, and are only a subset of many other technical options developed countries managed to substantially scale- available to countries for reducing water pollution. down the levels of organic pollution, nutrient loading (Many case studies in Chapter 4 mention monitoring and pathogen contamination in their rivers and lakes as part of solving their pollution problems. Although (as indicated by sinking river concentrations of BOD, monitoring is not a technical option in the sense of phosphorus, and faecal coliform bacteria) (EEA, 2014; Tables 5.1 and 5.2 in this chapter, it is a very important Hogan, 2014; OECD, 2008). Although some types of step in tackling pollution control, as emphasized in water pollution persist in developed countries (see Chapter 2.) Chapters 1 and 4), the water quality of many of their freshwater ecosystems has improved significantly.

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Table 5.1: Technical options mentioned for the specific water quality issues in the case studies (Chapter 4).

River Basin Upper Tietê Godavari Volta Chao Phraya Vaal Medjerda Elbe Hudson

Erosion, Organic Type of Organic Organic Pathogen Pathogen Eutrophi- Salinity salinity, chemical pollution pollution pollution pollution pollution cation nutrients pollution

Technical options employed

Pollution prevention XX

Treatment of wastewater X XXXX treatment

Safe reuse of wastewater X XX

Protection & restoration of XX XX ecosystems

Among the most established options is to lay out a now available for reducing water pollution loads are: network of sewers for collecting wastewater from • Pollution prevention different sources and delivering the wastewater • Wastewater treatment (conventional and to a conventional wastewater treatment facility, unconventional) as developed countries began to do decades ago. • The safe reuse of wastewater This has only been a partly successful strategy in developing countries because of the high energy • Ecosystem protection and rehabilitation costs of conventional treatment facilities, the lack Section 5.1 briefly reviews the specific measures of technical capacity to run these plants, and other that fall under these major categories and how these drawbacks. Moreover, pollutants from diffuse sources measures can be used to reduce sources of water such as urban surface runoff and irrigation return flows pollution. An overview of these measures and how are difficult to collect and treat, both in developing they apply to the different types of water pollution and developed countries. In other cases, specific sources is given in Table 5.2. The options are diverse types of pollutants, e.g. pharmaceutical residuals and and their feasibility depends on the type, intensity, some trace metals, are not effectively removed by and quantity of specific water pollutants as well as conventional treatment. Despite all these drawbacks, many other technical factors, which are discussed in gravity driven sewerage and conventional wastewater the text. treatment is often still a favourable option for bringing But selecting the right technical option is only one a water pollution problem under control. aspect of water pollution control. It is also important New options have arisen over the last few decades to develop effective management and governance and are worth considering. They complement (rather strategies. Some of these aspects are discussed in than replace) conventional wastewater treatment. If Section 5.2. wastewater treatment is included, the major options

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Table 5.2: Selected technical options relevant for different sources of pollution. Technical options marked with “+” are relevant to reducing the indicated source of pollution. This is not an exhaustive list of options.

Source of pollution

Domestic Domestic non- Urban surface Agriculture and Technical option Industry sewered sewered runoff sediment pollution

1. Pollution prevention

Increasing water use efficiency + + + +

Reduction of wastes produced + + + +

Urban green infrastructures + +

2. Treatment of wastewater

Mechanical/primary treatment + +

Biological/secondary treatment + +

Chemical/tertiary treatment + + Advanced treatment + + Constructed wetlands & natural treatment systems + + +

3. Safe reuse of wastewater

Use of stormwater +

Reuse of domestic wastewater and sludge +

Household greywater recycling systems +

Reuse of wastewater in industries +

4. Protection and restoration of ecosystems

Forest conservation / reforestation of river basins + +

Using natural wetlands for treatment of wastes + + +

River dilution + + + + + Flow regime restoration + + + + +

Targeted environmental dredging + +

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5.1 Technical Options

5.1.1 Pollution prevention “Pollution prevention”, or “source control of many circumstances, pollution prevention has been pollutants”, is the banning, avoidance, reduction, shown to be as effective as conventional wastewater or elimination of a contamination at the source. In treatment in reducing water pollution loadings.

Best practice example ‘Source control of phosphorus’ Prior to 1980, polyphosphates were used in detergents in large quantities because of their ability to bind calcium and magnesium ions and thus soften water. The phosphorus loading of many lakes and rivers, especially in OECD countries, increased dramatically with increasing detergent use after World War II. As a response, the use of phosphate in detergents was regulated in Central Europe beginning in the late 1970s. Consequently, phosphates were replaced by other water- compatible chemicals such as sodium aluminium silicate, and average phosphorus concentrations in wastewater were halved. This action, along with Year the upgrading of wastewater treatment plants, led to a decline in the phosphorus loading of many Trend of mean phosphorus concentrations in 11 alpine lakes Central European lakes to their pre-1950 levels. from 1940 through 2012. Data from EEA (2015).

Pollution prevention is achieved in various ways, as compost (such as the Ecosan systems). Another explained in the following paragraphs. option is to employ a greywater system which Increasing water use efficiency recycles household water used for washing purposes. Technically speaking, it is more practical One way to prevent water pollution is to use water to include these systems in new buildings than as efficiently as possible so that less wastewater is retrofit them into existing buildings. There produced. are many other alternatives, which differ in • Households. Water use can be made more efficient sophistication and costs. Some options are in the household by fixing leaky taps and toilets, very feasible and affordable for low income using water saving devices in toilet cisterns, taking households. showers rather than baths, and using water-saving • Manufacturing and industries. This includes washing machines and dishwashers. “Green chemistry” which aims to avoid the • Manufacturing and industries. Measures here release of hazardous substances into the water include the introduction of water efficient cycle. One example here is to add equipment at production processes, water recycling and an industrial facility to reduce or recover waste. wastewater reuse. Another is to modify the production of chemicals • Agriculture. This includes water efficient irrigation, so that less waste is produced. and tailwater return systems. • Agriculture. The main options here are nutrient Reduction of wastes produced and pesticide management which include Another pollution prevention strategy is to reduce minimising fertilizer and pesticide surpluses, the amount of wastes produced and thereby reduce changing crop rotation, and reducing surface run- the amount of wastes in wastewater. (See box “Best off through tile-drain management. practice example ‘Source control of phosphorus’”). Urban green infrastructures • Households. One option here is to use compost Controlling stormwater runoff from city surfaces is an toilets which do not require water and produce old problem, but new ways are being developed to deal

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with it. Traditionally, stormwater runoff is collected Urban “green infrastructures” also include pavement in large conduits and either delivered to a treatment that enhances stormwater infiltration, and structures plant or discharged directly to surface waters. An that reduce the infiltration of storm runoff into sewers. alternative approach, which is increasing in popularity, 5.1.2 Treatment of wastewater is “rainwater harvesting” through which water is A wide range of different options are available for stored on the urban landscape in natural depressions conventional and non-conventional treatment. Some or in artificial cisterns and then sometimes used for are single-stage systems; others, such as mechanical- watering parks and for other non-potable purposes. biological-chemical treatment, are a combination Constructing “green roofs” made up of plants that of different stages. Some include tailor-made pre- absorb and retain rainwater has become a simple treatment systems. (See box “Fuheis demonstration and popular way of lessening the immediate runoff site as best practice example of ‘Treatment of polluted of stormwater. In addition, green roofs make houses water’”). cooler in the summer and warmer in the winter and the roofs act as small habitats for a wide range of flora and fauna.

Fuheis demonstration site as best practice example of ‘Treatment of polluted water’ As part of the project IWRM-SMART (Sustainable Man- agement of Available Water Resources with Innovative Technologies), the Fuheis demonstration site near- Am man (Jordan) started operation in the autumn of 2009. Different technologies are operated at the site, including sequencing batch reactors, extended aeration systems, constructed wetlands, a sludge humification system and a sludge screening and anaerobic stabilization reactor. The facilities are used for identifying the combinations of technology that can successfully treat different wastewaters. The facilities are also used for the training of techni- cians, and to inform managers and decision makers about technical options for dealing with water pollution. Source: Manfred van Afferden (UFZ)

Mechanical/primary treatment still contains substantial amounts of nutrients and Primary treatment is used to remove larger particles other chemicals which require further treatment to and some of the finer particles as well, depending be removed. However, the microbiological processes on the set-up of the system. The key function of a in this stage of treatment can be optimized to boost mechanical system is to settle out particles in the the removal of nitrogen compounds such as nitrate wastewater by gravity. As a stand-alone solution it and ammonia, but only if the processes are controlled must be considered outdated but in combination correctly, e.g. with alternating periods or zones of high with more advanced treatment it is still very useful. and low oxygen concentrations. One consequence This is because pre-removal of larger particles makes of secondary treatment is that it produces a large the next steps in the treatment process much more amount of sludge which must be disposed of safely. efficient. On average, well run mechanical treatment Chemical/tertiary treatment systems may reduce the amount of organic matter by This treatment stage typically includes the use of 30–50 per cent, and nutrients by 10–20 per cent. specific additives, such as iron-sulphate, to remove Biological/secondary treatment phosphorus and other chemicals. Precipitation of This type of treatment involves the decomposition heavy metals is a common method to take the metals of wastes by a wide variety of microorganisms. out of the water phase and into the sludge phase. Since Secondary treatment helps in removing most of the tertiary treatment targets substances that are not organic matter and only part of the nutrient load. removed by more affordable primary and secondary Hence the effluent from this stage of treatment often treatment, it tends to be the most expensive stage of treatment.

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Advanced treatment wastewater is usually pre-treated to remove sand and Research is constantly advancing the state of grit. Well-dimensioned and -maintained wetlands wastewater treatment. For example, conventional can provide the same pollutant removal rates as treatment systems require large amounts of land traditional mechanical/biological treatment systems. which may not be available in cities; this lack of land Constructed wetlands are mainly used for treating has stimulated the development of very compact domestic wastewater low in chemicals because a high systems for specific types of wastewater. The concentration of chemicals can destroy the biological principles used in these new types of technology processes of the wetland. They are particularly suited are based on well-known but optimised mechanical/ for rural areas land is available for the wetland. One biological methods. Typical clients for new treatment drawback of constructed wetlands is that they store methods are hospitals, industries, and cruise ships. A large quantities of phosphorus, organic material, limitation of such systems is that they are adapted to and heavy metals in their soils and sediments, and a particular kind of wastewater having a narrow range this necessitates a periodic renewal of the treatment of characteristics. Wastewater outside this range could system. destroy the microorganisms that play an essential role 5.1.3 Safe reuse of wastewater in the treatment system. Use of stormwater Some advanced treatment facilities recover methane, There are a number of ways in which the harvesting a useful fuel, from the gasification of sludge and other and subsequent use of stormwater helps to reduce treatment processes. Often this fuel is used for the water pollution. First it prevents polluted stormwater internal fuel needs of the treatment facility. Some runoff from directly entering surface waters. Second, advanced treatment produce an excess of fuel which it helps reduce the frequency of stormwater overflows is sold or utilised in other public facilities. from sewer systems. Third, it replaces some water Constructed wetlands and natural treatment systems withdrawals from surface waters and therefore helps “Constructed wetlands”, usually consisting of reeds, maintain more consistent flows in the river system. are fabricated to mimic the purifying capacity of (See box “Singapore as a best practice example on natural wetlands. Before passing through the wetland, ‘Safe reuse of wastewater’”)

Singapore as a best practice example on ‘Safe reuse of wastewater’ No other city in the world is harvesting stormwater at the scale of Singapore. As a small island lacking natural aquifers and lakes, and with little land to collect rainwater, the city needs to maximize what it can harvest. With a network of drains, canals and 17 reservoirs of various sizes, two-thirds of the Singapore land area has been turned into a giant water cistern. The harvested water is used for recreational purposes and many other uses. Source: http://www.anmc21.org/english/bestpractice/images/img/ env_wat02_2.jpg

Reuse of domestic wastewater and sludge sludge, are treated to a hygienically safe state before The reuse of wastewater, excreta and greywater for further use. Treatment options include long term irrigating or fertilising crops is widespread and can storage, exposure to very high temperatures, and reduce or avoid water pollution by preventing these exposure to UV light. substances from directly entering surface waters. But Another safe way to reuse wastewater from the for reuse to be successful it must be carried out in a domestic sector is to use it for cooling or other safe and socially acceptable way, and this depends on purposes in closed production cycles in the industrial how the wastewater and waste is managed and on sector; this minimizes the risk that people will be various ethical, cultural and educational factors. The exposed to unsafe substances or organisms in the main task for managers is to ensure that wastewater, wastewater. Depending on the type of wastewater, and its by-products such as composts and sewage it may also be safe to use it for watering ornamental

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plants and fruit-growing bushes and trees, although Most treatment systems produce sludge which has to not for irrigating food crops such as leafy vegetables be managed carefully to avoid public health hazards. and root plants. One safe option is to use sludge as the feedstock for a A continuing problem is that not all dangerous biogas generator which produces methane-rich gases chemical substances in wastewater are removed that can be used for heating, cooking, and other energy by conventional treatment. Therefore, the reuse uses. The stabilized sludge can afterwards be used as a of treated wastewater and sewage sludge may fertiliser or soil amendment once it is confirmed to be inadvertently convey dangerous substances to soils free of dangerous substances. (See box “Best practice and groundwater. One solution is for these substances example on ‘Anaerobic Digestion System (ADS) biogas to be removed at the source, through “pollution systems’ in Ghana.”). As with treated wastewater, a prevention” actions as described above, before they good way to ensure that sludge is free of dangerous enter the wastewater stream. chemical substances is to remove these substances at the source through “pollution prevention”.

Best practice example on ‘Anaerobic Digestion System (ADS) biogas systems’ in Ghana Biogas Technologies Africa Limited (BTAL), located near Accra (Ghana), is providing low tech, innovative solutions to convert faecal matter, biodegradable healthcare waste and solid waste into biogas energy and nitrogen-rich plant fertiliser. Numerous institutions, including hospitals, hotels, educational centres, and food processing industries as well as private homes, have benefited from the low cost and low land requirements of the biogas plants. These plants can also be used in areas with unreliable or limited water supply and do not require electricity to operate. With support from UN-Habitat, UNIDO, and UNEP, BTAL is carrying out similar projects in Senegal, Nigeria, Uganda, Mozambique, Tanzania, South Africa, and Kenya. Source: John Idan

Household greywater recycling systems as sand filters (Ochoa et al. 2015) and helophyte Systems for treating and reusing greywater have treatment plants (Laaffat et al., 2015, Saumya et al. become relatively common worldwide (Al-Zu’bi et al. 2015). In other cases, different components from 2015, Ghrair et al. 2015, de Gois et al. 2015, Lam et conventional wastewater treatment are combined, al. 2015). By definition, “greywater” is wastewater for example, ozonisation units, UV disinfection units, from baths, showers, washing machines, dishwashers, adsorption set-ups, and filtration components (Kneer and kitchen sinks; “blackwater” is water from toilets et al. 2009). In still other cases, biological systems, (Birks & Hills 2007). Certain studies further divide such as membrane bioreactors and biologically greywater into “light greywater” (wastewater from aerated depth filters, are used. bathrooms, showers, and baths) and “dark greywater” Reuse of wastewater in industries (wastewater from washing machines, dishwashers, and kitchen sinks). Sievers et al. (2014) give the following There are many opportunities for wastewater reuse typical concentration ranges for dark greywater in in industry. For example process water can be re-used Europe: chemical oxygen demand 102 to 1,583 mg/L, for sanitation and other water uses at the industrial biochemical oxygen demand 56 to 427 mg/L, total sites. Depending on the circumstances, wastewater nitrogen 3 to 48 mg/L and total phosphorus 0.5 to 15 may also be used as boiler feed water or cooling mg/L. water. Some authors have proposed using industrial The degree of sophistication of the recycling system wastewater as input to bioenergy production (Ranade depends on the intended use of the treated greywater & Bhandari, 2014). (Ghaitidak & Yadav 2015, Teha et al. 2015). In some As with the reuse of wastewater in other sectors, a cases, comparatively simple processes are used such prerequisite for reusing industrial wastewater is to

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treat it to a safe and acceptable level. A wide spectrum aquatic ecosystems. Because they retain water and of technologies are relevant including precipitation have alternating dry and wet conditions with steep and sedimentation, biological treatment media bio-geochemical gradients, they act as filters of poor filtration, membrane filtration, ion exchange, reverse quality water that flows into them. Hence, their osmosis, and disinfection. Such treatment is used protection and restoration is an important element of to reduce or remove priority pollutants, pathogens, water quality management at regional or catchment biodegradable compounds, and metals and other scales. (See box ‘Danish Action Plan on the Aquatic non-biodegradable compounds. A complicating factor Environment’) for industrial wastewater treatment is the extreme River dilution variation of the quality and quantity of wastewater Rivers themselves can effectively dilute small loads of over time. Both treatment and economic efficiency non-persistent pollutants when river discharge is high can be improved by eliminating potentially damaging enough and consistent. However, a river cannot safely wastewater compounds at the source, before they dilute persistent pollutants, such as organic chemicals, enter wastewater streams. because these substances accumulate in the food web 5.1.4 Protection and restoration of ecosystems and in sediments. Also it is obvious that rivers with low River networks, lakes, reservoirs, and groundwater flows cannot successfully dilute pollutants that are are interconnected compartments of the hydrological discharged in large volumes. cycle and closely linked to the terrestrial environment. Flow regime restoration They provide many essential ecosystem services such Removing dams or artificial channels will restore a as drinking water, flood protection, nutrient cycling, more natural flow regime to a river and can sometimes means of transport, energy production, and self- mitigate water quality problems. For example, purification. Here we discuss their role as a controller removing a dam on an otherwise free-flowing river of water quality. may successfully reduce eutrophication and dissolved Forest conservation/reforestation in river basins oxygen problems occurring behind the dam. This is The headwaters of streams and rivers are typically because these problems are most likely related to the much steeper than their lowland parts. Therefore, long residence time and accumulation of nutrients in if they are thinly-vegetated they may have more the reservoir behind the dam. In this case, removing frequent rapid surface runoff and a higher rate of soil the dam and restoring the unrestricted flow of the erosion than lowland areas. If they are heavily forested river may remove the water quality problem. they will have a much lower rate of erosion, and a Targeted environmental dredging much smaller amount of sediment and nutrients will Environmental dredging is used to remove be transported from the land surface into freshwater contamination from targeted areas in river beds. This ecosystems. Hence, conserving the forest cover of technology is very specific and is designed to minimize headwaters, or re-introducing this forest cover, can resuspension of small sediment particles that may be be a very effective way of controlling downstream contaminated with PCBs, heavy metals, or other toxic water quality. (See ‘Catskill/Delaware watershed materials. Resuspension is avoided, for example, with conservation’ box). hydraulic dredges or similar machinery which function Using natural wetlands for treatment of wastes like large vacuum cleaners to remove contaminated Floodplains, riparian zones, and wetlands play a key sediments with strong suction pumps. role in the integrity, functioning, and biodiversity of

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Best practice example ‘Catskill/Delaware watershed conservation’ New York City obtains most of its water from the Catskill/Delaware watershed located upstream from the metropolitan area. Approximately 1.4 billion gallons of water (about 5.3 million cubic meters) are consumed daily by eight million New York City residents and one million upstate customers. At present, all of New York City’s drinking water is unfiltered. In order to maintain the quality of this water supply New York State [annually] spends about 100 million US$ for actively managing the forest catchment areas and compensating the farmers for using less fertiliser and reducing grazing. By comparison, it has been shown that the alternative to these actions – constructing a treatment plant for filtering the raw water to achieve sufficient water quality according to required standards – would require investments of about 7–10 billion US$ with annual operation and maintenance costs of about 110 million US$.

The Catskill watershed and water supply system for New York City (Source: NYC Dep. of Environmental Protection).

Best practice example ‘Danish Action Plan on the Aquatic Environment’ for controlling nutrient loads Danish inland and coastal waters deteriorated in the 1970s and 1980s leading to country-wide public and political concern. The cause was the high nutrient loading from point and diffuse sources. Diffuse sources play a major role because more than 60 per cent of the total area of Denmark is cultivated land, and livestock production and density is high. Under the so-called ”Action Plan on the Aquatic Environment II”, a series of natural wetland rehabilitation projects were carried out to control nutrient losses from agricultural areas to the freshwater and marine environment. These projects included the re-establishment of 16,000 hectares of “wet meadow” to help reduce nitrogen leaching, and 20,000 hectares of formerly removed forests. It was estimated that nitrogen loads were reduced by 127,000 tonnes N/yr under the action plan, equivalent to a 40 per cent reduction of overall nitrogen discharges into the aquatic environment. Aerial view of large scale wetland rehabilitation project in the Skjern River watershed under the Danish Action Plan on the Aquatic Environment (Source: Danish Forest and Nature Agency)

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5.2 Other issues for protecting water quality

5.2.1 Water quality protection and the Post- Furthermore, it is possible to begin restoring stretches 2015 Development Agenda of rivers and lakes that are already polluted by As emphasised throughout this report, water is a key building on experience from other parts of the world. requirement for the sustenance of human life and For example, Chapter 4 presents the example of the sustainable development. It is not surprising, then, restoration of a large segment of the Upper Tietê River that water quality issues are strongly linked with other in Brazil. Elsewhere in Latin America, the Medellin development themes such as poverty, hunger, health, River in Colombia was restored through the efforts education, gender inequality, and environmental of the Medellin River Sanitation Programme and sustainability. In Chapter 3, for example, it was integrated urban water management (Kraemer et al., reported that the groups most vulnerable to pathogen 2001). Water quality in the eastern part of Columbia water pollution are women and children who still rely was improved by employing the polluter pays principle on surface waters for their domestic needs. It was also which led to an expansion of wastewater treatment recounted that poor fisher are vulnerable to organic (Kraemer et al., 2001). In Africa, the water quality pollution and smallholder farmers to salinity pollution. behind the Hartbeespoort Dam in South Africa was restored through biological remediation (Keto, 2013 The lack of access of poor people to water of adequate and Kraemer et al., 2001). Many lakes and rivers have quality contributes to socio-economic inequalities. On been restored in Europe, including Lakes Norvikken the positive side, since 1990 more than two billion and Mälaren located in Sweden which were revived by people have gained access to improved sources of reducing phosphorus loadings (Schindler, 2012). drinking water through programmes associated with the Millennium Development Goals (WHO/UNICEF The countries along the Elbe River collaborated 2014b). Nevertheless, while access to drinking successfully in restoring their river through an effective water has increased, the quality of surface waters institution called the International Commission used for household water supply in many parts of for the Protection of the Elbe (see Chapter 4). The the developing world continues to deteriorate as Commission championed wastewater treatment articulated in previous chapters. Therefore, it is very in the public sector, conveyed water management significant that the new Sustainable Development reports to the public, and carried out many other Goals (SDGs) under the Post 2015 Development activities to promote water quality management in Agenda have ambitious targets not only for access to the basin (Dombrowsky, 2008). Meanwhile, the Rhine drinking water, but also for water quality (UN, 2015). Action Programme brought together its riparian states A holistic and coherent approach is needed to tackle in a successful effort to restore the water quality of this and other goals. A concerted global education the Rhine (Raith, 1999; Bernauer, 2002). Similarly, and awareness-building campaign around water the London River Action Plan was instrumental in quality issues will be needed, with targeted regional restoring the integrity of the Thames River (London and national campaigns that connect water quality to Rivers Action Plan, 2009). issues of cultural and historical importance. Explaining One lesson from these and other examples presented the necessity of good water quality to households, the in Chapter 4 is that an action plan, agreed upon by media, policy makers, business owners, and farmers all the main actors in a river basin, is a key step in can have a tremendous impact on protecting and restoring rivers and lakes. Another lesson is that it is restoring water quality. useful to set up a collaborative institution, such as an 5.2.2 Precedents for restoration international commission, for developing and carrying out the action plan. It is not necessary for developing countries to go through the same cycle of increasing water pollution, widespread 5.2.3 Financing and governance for protecting degradation of freshwaters, and eventual recovery, and restoring freshwaters that developed countries went through decades ago. It is generally accepted that the infrastructure for The many different technical and management options managing water, wastewater and sanitation will available for coping with increasing pollution loads are require considerable additional investments. Because given in Section 5.1 above. of the high costs of conventional wastewater collection

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and treatment, pollution control agencies usually Over the years, it appears that the barriers to combine financing with cost recovery measures. controlling water pollution have stubbornly remained These might include, for example: direct cost recovery in place (Camdessus, 2003; UN-Water, 2015a). For from the user/polluter (also known as ”beneficiary example, many governments and institutions from charges”), indirect local taxation (typically using the river basin to country level still have not adopted a property tax as a vehicle), and subsidies from other strategic approach to wastewater management based government departments. Cost recovery also requires on sound planning and evidence. Another important sound regulatory frameworks and policies. Without barrier, especially in developing countries, has been this enabling environment, the investments needed to the fragmentation of institutional responsibilities for support water pollution control will be inaccessible to wastewater management which prevents efficient most developing countries. coordination of actions. This was brought up in Chapter Financing of wastewater infrastructure in developing 4 in the discussion of water quality management in the countries comes from various sources including Godavari River Basin (Table 5.3). In addition, several overseas development assistance programmes of case studies in this chapter highlighted the importance donor countries, multinational financial institutions, or of participatory processes, such as “Research in Action” international commercial lending and credit agencies. REACT in Tunisia, including community involvement and inclusion of indigenous knowledge. One way to achieve sustainable financing for water pollution control is to adopt a mix of economic policy But there are signs that some developing countries instruments that foster an efficient allocation and use are giving higher priority to wastewater and water of water and protect and reduce the pollution of water resources management. Two examples are the resources. As highlighted by the fourth principle of the newly adopted Africa Water Vision for 2025 and the Dublin statement on sustainable water management establishment of the African Ministerial Council on adopted by the UN in 1992, all uses of water have Water (AMCOW) (Meena, et al, 2010). These steps an economic value. Managing water as an economic contribute to the good governance needed to tackle good is an important way of achieving efficient and water quality degradation. Good governance, including equitable water use and of encouraging conservation evidenced-based policymaking and the effective and protection of water resources. The use of economic application and enforcement of legal and institutional instruments in water resources management is often restrictions on water pollution, will be a prerequisite more cost effective than other instruments, because to meeting the global water quality challenge. Many it helps internalise the costs of water pollution (Klarer examples of good governance solutions from the case et al., 1999). studies in Chapter 4 are given in Table 5.3.

Table 5.3: Summary of governance solutions mentioned in the case studies (Chapter 4).

Programmes and policy Case study Pollution problem Governance bodies * Interest organisations instruments

São Paulo Upper Tietê River Basin Tietê River Cleanup Upper Tietê Organic pollution Environment Agency Committee Program

State Pollution Control Boards, State Groundwater Godavari Organic pollution Boards, State Water Resources/ Irrigation Department, Urban Local Bodies

Convention on the Status Volta Pathogen pollution Volta Basin Authority of the Volta River

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Table 5.3: cont.

Programmes and policy Case study Pollution problem Governance bodies * Interest organisations instruments

Electricity Generating National Economic and Social Authority, Royal Development Plan, Plan Irrigation Department, for Natural Resources and Chao Phraya Pathogen pollution Pollution Control Environment Management, Department, Regional Wastewater discharge fees Environment Office (Polluter-Pays-Principle)

Water Act of South Africa, Department of Water Law-binding management Vaal Salinity and Sanitation objectives (Resource Quality Objectives)

Direction Générale des Ressources en Erosion, salinity, Medjerda Eau, Agence Nationale nutrients de Proctetion de l’Environnement

European Water Framework International Directive, Urban Wastewater Commission for the Treatment Directive, Nitrate Elbe Eutrophication Protection of the Elbe Directive, Hazardous River, River Basin Substances Directive, Floods Community Elbe Directive

Department of Environmental Organic chemical Conservation, New Hudson Hudson River Estuary Program pollution York City Department of Environmental Protection

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5.3 Some questions for a full assessment This chapter has clearly shown that many technical • What are the types and sources of water pollution and governance solutions are available to meet related to various socio-economic and eco- the water quality challenge. These include new hydrological conditions? approaches that were not available to the developed • What is the efficiency and success rate of existing countries some decades ago when population growth water pollution measures and programs? and increased economic activity led to a substantial • What are the most important drivers of water increase in water pollution. It was also shown that pollution? no single set of solutions will work everywhere. This is because of the great variation in types of water • For a particular location, what is the relationship pollution, sources of water pollution, socio-economic between pressures, impacts, and responses to conditions, and hydro-ecological boundary conditions. water quality degradation? On the other hand, similar water quality challenges • What are effective clusters of technical and are occurring around the world even if the locations governance options for particular archetype and situations are very different. Therefore, it may be water quality problems? possible to develop different packages of technical and • What are the most useful indicators for tracking governance options that can be used in many different progress towards the water quality Sustainable river basins to deal with similar problems. In order to Development Goal? identify these packages, a full global water quality assessment should address the following questions:

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Buch_UNEP_hintere_Kapitel1504.indb 94 09.05.16 17:19 Literature

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Appendix-1

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Towards a global assessment global a Towards Towards a global assessment assessment global a Towards

A Snapshot of the World’s Water Quality: Water World’s the of Snapshot A A Snapshot of the World’s Water Quality: Quality: Water World’s the of Snapshot A

www.unep.org www.unep.org www.unep.org

e-mail: [email protected] [email protected] e-mail: [email protected] e-mail:

Fax: +254 20 762 3927 3927 762 20 +254 Fax: 3927 762 20 +254 Fax:

Tel.: +254 20 762 1234 1234 762 20 +254 Tel.: 1234 762 20 +254 Tel.:

P.O. Box 30552 - 00100 Nairobi, Kenya Kenya Nairobi, 00100 - 30552 Box P.O. Kenya Nairobi, 00100 - 30552 Box P.O.

United Nations Environment Programme Programme Environment Nations United Programme Environment Nations United

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Appendix-2

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Appendix

Appendix A A1 Available data from GEMStat (1990–2010) Table A.1: Overview of data availability in the time period 1990-2010 based on GEMStat. Stations were assigned to global river basins (Source: Major River Basins of the World/Global Runoff Data Centre. Koblenz, Germany: Federal Institute of Hydrology BfG). Maximum number of measured parameters = 26. Number of measurements = all measurements of all parameters of all stations within a river basin.

Data No. of No. of measured No. of Subregion River basin available stations/ parameters measurements from–to RB Nile 1990-2010 2 15 425 North-Africa Oum-Er-Rbia River 1994-2010 1 13 2,186 Sebou 1990-2010 2 14 3,098 Groot Kei 1990-2010 1 9 1,394 Groot Vis 1990-2010 1 9 1,686 Incomati 1990-2009 1 9 1,452 Indian Ocean Coast 1990-2010 3 9 1,730 South-Africa Limpopo 1990-2010 7 9 4,877 Olifant 1990-2010 1 9 972 Orange 1990-2010 5 10 6,281 South Atlantic Coast 1990-2010 1 9 1,874 Tugela 1990-2010 2 10 1,734 Niger 1992-1996 7 12 463 Pra 1991-1994 1 11 283 West-Africa Senegal 1991-2000 5 11 129 Volta 1991-1995 1 12 331 Colorado (Caribbean Sea) 1990-1996 17 14 2,790 Grijalva-Usumacinta 1990-1996 2 15 1,366 Panama Canal 2003-2010 51 14 16,296 Panuco 1990-1996 1 15 369 Central-America Papaloadan 1990-1996 1 16 622 Rio Boqueron 2003-2010 1 14 1,075 Bravo 1990-1996 2 16 1,134 Santiago-Lerma-Chapala 1990-1996 1 16 257 Alabama 1990-2001 4 2 307 Alsek 1992-2004 1 5 172 Churchill 1990-1997 1 9 181 Fraser 1990-2004 3 8 1,371 Hudson 1990-2001 8 9 383 Mackenzie 1990-2004 4 9 749 Mississippi 1990-2005 59 11 5,427 Nelson-Saskatchewan 1990-1997 3 9 600 North-America Bravo 1990-2005 16 10 2,509 Sacramento 1990-2002 12 10 694 Skeena 1990-2004 1 7 561 St. Croix 1990-1996 1 6 281 St. John 1992-1994 1 7 69 St. Lawrence 1990-2005 9 9 891 Susquehanna 1990-1995 1 10 307 Yukon 1990-2005 6 9 490

Appendix-3

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Data No. of No. of measured No. of Subregion River basin available stations/ parameters measurements from–to RB Amazon 1993–2010 461 17 7,223 Doce River 1997–2010 3 14 1,578 Guandu River 2001–2010 1 11 1,198 Jequitinhonha River 1997–2010 3 14 1'457 Meia Ponte River 2001–2010 1 11 357 Oyapock 2004 4 5 20 South-America Paraguacu River 2008–2010 2 11 240 Parana 1990–2010 169 19 19,660 Parnaiba 1992–2010 20 14 500 Sao Francisco 1990–2010 45 16 2,487 Tocantins 1996–2010 82 15 1,176 Uruguay 1990–2010 37 15 1,479 Bei Jiang/His 1990–1996 2 15 1,268 Chang Jiang 1990–1997 3 17 2,276 Han 1990–2010 3 13 2,939 Hwang Ho 1990–1997 2 15 1,306 East-Asia Japan* 1990–2010 17 18 31,117 Liao 1990–1997 1 12 892 Min 1990–1996 1 12 810 Qiantang 1990–1996 1 12 655 Cauvery 1990–2008 8 15 12,112 Chaliyar 1990–2008 2 15 4,124 Ganges-Brahmaputra-Meghna 1994–2010 5 10 513 Godavari 1990–2008 6 15 8,273 Indus 1990–2003 4 15 4,589 Krishna 1990–2008 7 15 13,664 Mahandi 2001–2008 5 15 2,960 Mahi 1990–2008 2 15 3,450 South-Asia Narmada 1990–2008 5 15 6,260 Penner 1990–2008 1 15 991 Periyar 1990–2008 2 15 4,126 Sabarmati 1990–2008 3 15 4,082 Sahyadri 1990–2008 10 15 8,329 Sri Lanka* 2003–2010 27 12 12,198 Subarnerekha 1992–2008 4 14 3,915 Tapti 1990–2008 4 15 6,503 Chao Phraya 1990–1993 3 11 308 South-East-Asia Indonesia* 1990–1994 6 15 2,163 Mekong 1990–2009 72 14 50,107 Amur 1990–2010 2 8 822 Danube 1990–1996 2 9 937 Don 1990–2010 1 8 347 Dvina-Pechora 1990–2010 5 8 3,070 Kolyma 1990–2010 1 7 590 Lena 1990–2010 2 7 620 East Europe Narva 1990–2010 2 7 391 Ob 1990–2010 9 7 5,611 Oder 1992–2003 3 9 3,297 Vistula 1992–2003 3 8 3,168 Volga 1990–2010 4 7 2,059 Yenisey 1990–2010 5 7 3,608

Appendix-4

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Data No. of No. of measured No. of Subregion River basin available stations/ parameters measurements from–to RB Dee 1990–2005 1 9 923 Denmark* 1990–1996 4 5 1,070 Forth 1990–2005 1 9 1,165 North West England 1990–2005 1 10 1,213 Northumbria 1990–1995 3 4 598 Oulu 1993–1995 1 3 101 Northern Europe Pasvik 1993–1995 1 3 95 Severn 1990–2005 1 11 1,154 South West 1990–2005 1 11 1,247 Thames 1990–2005 1 11 1,110 Torne 1990–1998 2 7 304 Trent 1990–2005 1 11 1,253 Tweed 1990–1996 1 10 827 Douro 1990–1995 7 5 1,799 Ebro 1990–1995 3 5 991 Guadalquivir 1990–1995 3 5 903 Guadiana 1990–1995 4 5 1,047 Southern Europe Italy* 1990–1995 8 6 1,609 Po 1990–1995 8 6 2,295 Portugal* 1990–1994 2 5 478 Tagus 1990–1995 6 10 1,872 Turkey* 1993–2002 7 4 1,170 Danube 1990–1996 7 9 660 Elbe 1990–1995 4 9 830 Garonne 1990–1996 4 8 1,224 Loire 1990–1996 5 8 2,062 Meuse 1990–2010 18 12 7,178 Oder 1993–1995 1 4 138 Western Europe Rhine 1990–2003 19 12 10,708 Rhone 1990–2002 8 9 4,729 Schelde 1990–2010 49 13 25,045 Seine 1990–1996 4 9 1,904 Weser 1990–1995 2 9 666 Yser 2001–2010 3 11 1,671 *Not all of GEMStat stations could be assigned to a river basin. In this case, the number of stations, measurements, and parameters of a country were listed.

Appendix-5

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Appendix B

B1 WorldQual – model description WaterGAP3 is made up of two main components: (i) a water balance model to simulate the characteristic B1.1 The modelling framework macro-scale behavior of the terrestrial water cycle WorldQual is a continental scale water quality model in order to estimate water availability (Alcamo et al., used to increase understanding of large scale water 2003; Müller Schmied et al., 2014; Schneider et al., quality patterns, support large scale assessments of 2011; Verzano 2009; Verzano et al., 2012), and (ii) a water quality degradation, and relate water quality water use model to estimate water withdrawals and degradation to threats to human health, food security, consumptive water uses for agriculture, industry, and and aquatic ecosystems. domestic purposes (aus der Beek et al., 2010; Flörke WorldQual simulates loadings and in-stream et al., 2013). WaterGAP3 also operates on a 5 x 5 arc concentrations of different water quality parameters minute spatial resolution (see Figure B.1). on a 5 by 5 arc minute spatial grid (about 9 by 9 km at Using a time series of climatic data as input, the the equator). It has been tested and applied in several hydrological model calculates the daily water balance previous studies, e.g. Malve et al. (2012), Punzet at al. for each grid cell, taking into account physiographic (2012), Reder et al. (2013), Reder et al. (2015), Voß et characteristics such as soil type, vegetation, slope, al. (2012), and Williams et al. (2012). and aquifer type. Runoff generated on the grid cells WorldQual calculates loadings to rivers and the is routed to the rier basin outlet on the basis of a resulting in-stream concentrations based on the global drainage direction map (Lehner et al., 2008), hydrological information simulated by WaterGAP3 taking into account the extent and hydrological (see below) and based on standard equations of water influence of lakes, reservoirs, dams, and wetlands. quality dynamics. It has a monthly temporal resolution. The climate input for the hydrology model consists Up to now it has been used to simulate biochemical of precipitation, air temperature, and solar radiation. oxygen demand (BOD5), faecal coliform bacteria (FC), These data come from the WATCH data set (Water and total phosphorus (TP), total nitrogen (TN) and total Global Change) applied to ERA-Interim data (WFDEI) dissolved solids (TDS) (Malve et al., 2012; Voß et al., for the time period 1979–2010 (Weedon et al. 2014). 2012; Reder et al., 2013; Reder et al., 2015; Williams The climate data have a temporal resolution of one et al., 2012). day and a spatial resolution of 0.5° by 0.5° (latitude WorldQual is linked to a global integrated water model and longitude, respectively) downscaled to the 5 arc “WaterGAP3” within a common modeling framework. minute grid cells.

spatial: 5’ spatial: 5’ temporal: daily temporal: monthly results: daily / monthly results: monthly discharge, runoff, WaterGAP3 flow velocity WorldQual Hydrology Model Water Quality Model

consumptive return water use flow

spatial: 5’ temporal: daily results: daily / monthly / yearly

WaterGAP3 Water Use Models

agriculture domestic manufacturing electricity production

Figure B.1: Overview of the WaterGAP3 modelling framework (Verzano 2009, modified).

Appendix-6

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B1.2 Pollution loadings Figure B.2 illustrates the point and diffuse sources represented in the WorldQual model. Point sources B1.2.1 Sources of pollution include domestic sewered wastewater, wastewater Loadings are calculated for point sources and diffuse from manufacturing industries and urban surface sources for the following parameters: runoff. Diffuse sources include agriculture and • faecal coliform bacteria (FC; pathogen pollution), background. The model also takes into account non- • biological oxygen demand (BOD; organic sewered domestic sources, of which some sources are pollution), handled as point sources, and some as diffuse sources • total dissolved solids (TDS; salinity pollution), and (See B1.2.3). • total phosphorous (TP; eutrophication).

point sources diffuse sources

Domestic Manufacturing Domestic Agriculture Urban Background • sewered • wastewater • non- • inorganic fertilizer surface • atmospheric runoff • non-sewered sewered • livestock wastes deposition • irrigation return flows • weathering • vegetation and soil

Figure B.2: Pollutant loading sectors in WorldQual categorized as either point sources or diffuse sources.

B1.2.2 Domestic sewered sector years 1990, 2000 and 2010. These data are applied Loadings from the domestic sewered sector are to the years 1990–1995, 1996–2004 and 2005–2010, calculated on a grid cell level by multiplying a per respectively. Further information on efficiencies of capita emission factor (BOD, FC, TDS, and TP) with the STPs were collected for several countries and applied urban and rural populations connected to a sewage as continental averages (Table B.1). system (Williams et al., 2012). The resulting domestic Gridded population data are available from the sewered loadings are then abated depending on History Database of the Global Environment (HYDE) the level of wastewater treatment. National values version 3.1 (Klein Goldewijk, 2005; Klein Goldewijk for percentages of primary, secondary, and tertiary et al., 2010) for the time period 1990–2005. For the wastewater treatment of sewage treatment plants remaining period 2006–2010, national data from (STPs) are downscaled to the grid-cell level to define UNEP (2015) were allocated to grid cells based on the a cell-specific reduction rate. Additionally, reduced gridded population density of the year 2005. treatment efficiency due to deficiencies of STPs is BOD per capita emission factors were collected from taken into account. Data are available from the WHO/ the literature. If no data were available, an average per UNICEF Joint Monitoring Programme (2013) for the capita emission factor was calculated per region.

Table B.1: Default sewage treatment plants efficiency.

Region Regional average [%] Reference Murray and Drechsel (2011), UNEP/GEF (2009), FAO and WHO (2003), Africa 58 WHO CEHA (2005), Water Affairs South Africa.(2011) Tacis (2000), CPCB (2005), CPCB (2009), MoP COSIT (2011), UNECE Asia 59 (2009), Government of Mongolia (2012), Shukla et al. (2012), Murtaza and Zia (2012), UNDESA-DSD (2004), UNECE (2012 a, b) Latin America 47 UNEP (1998), Ojeda and Uribe (2000), Lopera Gomez et al. (2012)

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Table B.2: Default BOD per capita emission factors per GEO region.

Regional average Region Reference [g/cap/day] Africa 37 Metcalf & Eddy et al. (2014), UNEP (2000), Williams et al. (2012) Asia 40 IPCC (2006), Williams et al. (2012) Latin America 56 Metcalf & Eddy et al. (2014), Williams et al. (2012)

Regional numbers (Table B.3) have been derived al. (2007). Several values within the range given by from the concentration of FC in human excreta taking the different references for the human per capita FC into account differences in diet, climate, and state excretion were tested with the model. During this of health (Feachem et al., 1983). Assumed reduction testing all parameters except the human per capita rates for primary, secondary, and tertiary treatment excretion were kept constant. Best results of simulated are intermediate values from Dorner (2004); Endale et FC in-stream concentrations compared to measured al. (2012); George et al. (2002), Hwang (2012), Qureshi FC in-stream concentrations were achieved with the and Qureshi (1990), Saleem et al. (2000), Samhan et numbers provided in Table B3 (see Reder et al., 2015).

Table B.3: Default FC per capita emission factors per GEO region. Regional differences arise from diet, climate, and state of health.

Regional average Region Reference [cfu*/cap/year] Africa 170*1010 Feachem et al. (1983), Finegold (1969), Maier et al. (2009), Moore and Holdeman (1974); Reder et al. (2015), Schueler and Holland Asia 700*1010 (2000), van Houte and Gibbons (1966), Zubrzychi and Spaulding Latin America 500*1010 (1962).

* cfu: colony forming unit

Based on UNEP (2000) and Mesdaghinia et al. (2015) a Waste loadings from onsite disposal (e.g. septic tanks) TDS emission factor of 100 g/cap/day was assigned to are calculated by multiplying a per capita emission all three continents. factor with the population connected to these disposal The TP per capita emission factors were calculated types. A release factor is applied to estimate the final as follows. First, the protein per capita consumption loading which enters the stream. per country and year was used from FAOSTAT (FAO, Waste loadings from open defecation are calculated 2014). It is assumed that about 16 per cent of the by multiplying the emissions per capita per year times protein is nitrogen whereof, on average, 36.5 per cent a release rate of 0.1 per cent (from Section B1.2.7). is excreted by the human digestive tract (van Drecht This annual loading is then transported to a stream on et al., 2009). Second, the TP per capita emission is a monthly basis proportional to monthly runoff from about one-sixth of the nitrogen emission (van Drecht WaterGAP3. The emissions per capita for BOD, FC, et al. 2004). Continent-specific averages of protein TDS, and TP follow the assumptions in Section B1.2.2. consumption were taken in case country-specific Waste loadings from hanging latrines are calculated by protein consumption data were not available. multiplying the emissions per capita per year times the B1.2.3 Domestic non-sewered sector population using this sanitation practice. No reduction For the human waste produced where sewers are not takes place as the feces are directly disposed into the used, three types of sanitation practices are accounted surface waters. for: (i) waste produced with some type of private on- Data on different sanitation practices are derived from site disposal, such as septic tanks, pit toilets, bucket the WHO/UNICEF Joint Monitoring Programme (JMP) latrines etc. (diffuse source), (ii) waste produced where for Water Supply and Sanitation country files between people practice open defecation (diffuse source), and 1980 and 2011 (JMP, 2013), national databases, (iii) waste produced where people use hanging latrines reports, and a literature search. As for the domestic (point source). sewered sector, data are only available for the years

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1990, 2000, and 2010, and assumed to be unchanged For FC, the effluent concentration was assumed to over 5 year periods. 3.55*106 cfu/100ml according to Ayoub et al. (2000), B1.2.4 Manufacturing sector Bordner and Carrol (1972), Caplenas et al. (1981), Caplenas and Kanarek (1984), Clark and Donnison Loadings from the manufacturing sector are calculated (1992), Das et al. (2010), Ekundayo and Fodeke (2000), by multiplying the average raw effluent concentration Gauthier and Archibald (2001), Hoyle-Dodson (1993), times the return flow from manufacturing industries Knittel et al. (1977), McCarthy et al. 2001), Megraw (Williams et al., 2012). The manufacturing load is and M. Farkas (1993), Pramanik and Abdullah-Al- reduced by a reduction factor depending on the Shoeb (2011). treatment level following the assumptions made for the domestic sector. Treatment rates and deficiencies For TP raw effluent concentrations from Europe (6.2 of sewage treatment plants are assumed to be the mg/l) are also applied to industrial sources in Africa, same as in the domestic sewered sector. Manufacturing Asia and Latin America (Demirel et al., 2005; Johns, wastewater volumes are calculated by the water use 1995; Gönen, 2005; Kim et al., 2007). model of WaterGAP3. B1.2.5 Urban surface runoff A representative value of 400 mg/l was assigned to the Loadings generated from urban surface runoff are effluent concentration of BOD from industrial sources calculated by multiplying the typical event mean based on literature (Al-Kdasi et al., 2004; Azmi and concentration by the urban surface runoff produced Yunos, 2014; EEAA, 2002; Haydar et al., 2014; Mortula on each cell (Williams et al., 2012). The resulting load and Shabani, 2012; UNEP, 1998; UNEP, 2000; Williams is assumed to be reduced to the same treatment et al., 2012). levels assumed for the domestic sewered sector. The For TDS, the effluent concentration was assumed to be hydrology module of WaterGAP3 provides the urban 3000 mg/l according to Al-Kdasi et al., 2004; Azmi and surface runoff rates. Junos, 2014; EEAA, 2002; Haydar et al., 2014; Jain et Assumptions and literature for the event mean al., 2003; Kang and Choo, 2003; Metcalf & Eddy, 2014; concentrations (EMCs) of BOD and TDS for different Mortula and Shabani, 2012; Tas et al., 2009; Williams sub-regions are shown in Tables B.4 and B.5. et al., 2012).

Table B.4: Default BOD event mean concentrations (EMC).

Region/Sub-region Regional EMC* [mg/l] Reference

Northern Africa, South Africa 19 Chrystal (2006)

Central Africa, Eastern Africa, Adedeji and Olayinka (2013), Adekunle et al. (2012), Western Africa, Southern Africa 62 Alo et al. (2007) (except South Africa)

South Africa 12 Chrystal (2006)

West Asia 19 Chrystal (2006)

Choe et al. (2002), Chow et al. (2013), Dom et al. (2012), Ho & Quan (2012),Luo et al. (2009), Karn Asia and the Pacific 105 & Harada (2001), Lee & Bang (2000), Li (2010), Maniquiz et al. (2010), Nazahiyah et al. (2007), Sharma et al. (2012), Yusop et al. (2005)

Latin America 12 Derived from Europe

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Table B.5: Default TDS event mean concentrations (EMC).

Region/Sub-region Regional EMC [mg/l] Reference

Africa 178 Wondie (2009)

Asia 246 Sharma et al. (2012), Zope et al. (2008)

Latin America 205 Al-Houri et al. (2011)

FC event concentrations vary widely. For example, FC and BOD the release rates of manure vary with they were measured to be around 104 cfu/100ml to manure type and differ according to the source of 106 cfu/100ml in stormwater runoff in South Africa literature (e.g. EPA, 2003; Ferguson et al., 2007). The (Jagals, 1997), 109 cfu/100 ml in China (Thomann and best estimate of release rates was found to be 0.1 per Mueller, 1987), and 104 to 106 in the USA (Erickson et cent. Release rates for TP are calculated as a function al. 2013). An intermediate value of 106 cfu/100 ml was of land surface runoff and soil erosion. The decay of FC assumed for all three continents. contained in stored manure or after manure is applied An average TP event mean concentration of 2.04 mg/l to soil is described by Chicks law (Crane and Moore, was assumed for all three continents based on Lee and 1986). The FC decay rate in this case is assumed to be Bang (2000), Ho and Quan (2012), Luo et. al (2009), the same as in Europe (Reder et al., 2015). Manure and Taebi and Droste (2004). application is assumed to take place all year round because of the continuous presence of livestock. To B1.2.6 Agricultural inorganic fertilizer calculate the wash-off of pollutants from land surfaces, Inorganic fertilizer is assumed to be applied to all the land surface runoff from the hydrology module of agricultural grid cells and is an important source of WaterGAP3 is used. TP loadings. Baseline fertilizer application rates of B1.2.8 Agricultural irrigation phosphorus were estimated from FAO (2006) for the 21 In WorldQual TDS loadings from irrigated agriculture different crop types distinguished by the WaterGAP3 were estimated by multiplying a mean irrigation model. The baseline data are representative for the drainage concentration by the irrigation surface time period 1995 to 1999. return flows calculated by the water use model of For earlier and later time periods, baseline data are WaterGAP3. Mean irrigation drainage concentrations scaled by national fertilizer application rates (IFA, 2014) show high variations from 1,000 mg/l up to 8,000 averaged over 5-years-periods 1990–1994, 2000–2004 mg/l in Asia. To account for the regional differences, and 2005–2010. (Five year periods are used to smooth salt emission potential classes (SEPC) were defined out uncertainties of annual fertilizer use.) as described in Voß et al. (2012) and Williams et al. TP loadings from industrial fertilizer that reach the (2012). The definition of SEPC is based on natural surface water system are calculated as a function of salt classes (SC) and the gross domestic product per land surface runoff and soil loss. capita classes (GDPC). Natural SC are a combination of B1.2.7 Agricultural livestock wastes primary salt enriched soils (S) and arid–humid climate To calculate the amount of BOD, FC, TDS, and TP conditions (H). The highest SEPC was set to 3,500 mg/l loadings from livestock (manure) the approach of for developing countries (Bakker et al., 1999; Chen et Sadeghi and Arnold (2002) is applied. Here, the l., 2011; Irrigation Department Lahore, 2014; World amount of the relevant constituent in manure is Bank, 1999), while the lowest SEPC was set to 165 multiplied with an appropriate release rate and the mg/l (cf. B1.2.9). These values reflect the range from surface runoff. The amounts of BOD, FC, TDS, and TP arid regions with salt affected soils and low irrigation in different types of manure are derived from ASAE technique standards (highest SEPC class) to humid (2003) and SCS (1992). To consider different levels of regions with no salt affected soils, and likely high animal nutrition on different continents, the amount irrigation technique standards (lowest SEPC class). of manure constituents are corrected by a livestock B1.2.9 Background loadings conversion factor from FAO (2003) following the A certain amount of phosphorus enters drainage approach of Potter et al. (2010) for nutrients. For basins in the form of atmospheric deposition. In

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the present study, global gridded estimates of TP retention is empirically calculated with hydraulic load deposition rates were taken from Mahowald et al. (Behrendt and Opitz, 1999). Hydraulic load is defined (2008). Additionally, natural phosphorus loads also as the annual runoff as calculated by WaterGAP3 originate from weathering. WorldQual’s estimates of divided by the surface area of the respective lake P-release by chemical weathering are derived from (Hejzlar et al., 2009). data of the global analysis of Hartmann et al. (2014). B1.5 Model testing Large amounts of background salinity in rivers come Data used for model calibration and testing were from weathering processes or surface salt deposits in kindly provided from national and international river basins. Background concentrations of TDS were databases of the Agencia Nacional de Aguas, Brasil; estimated by averaging GEMStat TDS measurements Department of Water and Sanitation, Republic of from pristine stations and sorting these data according South Africa; Dirección Ejecutiva de la Comisión to 55 soil types from the FAO Harmonized World Trinacional para el desarrollo de la Cuenca del Río Soil Database (Fischer et al. 2008). These data were Pilcomayo; Instituto de Hidrología, Meteorología y then applied as background concentrations in each Estudios Ambientales, Colombia; Instituto Nacional grid cell according to the type of soil in that grid de Meterologia e Hidrologia (INAMHI), Ecuador; cell. For respective soil types, these background TDS Mekong River Commission; Ministerio del Medio concentrations ranged between 5 mg/l and 832 mg/l. Ambiente, Gobierno de Chile, Chile; Pollution Control However, about 10 per cent of all river reaches have Department (PCD), Ministry of Natural Resources natural background greater than 450 mg/l the level and Environment, Thailand; Secretaría de Ambiente y used in this pre-study to designate “moderate” salinity Desarrollo Sustentable de la Nación (SADS), Argentina; pollution. For soil types not covered by GEMStat United Nations Global Environment Monitoring measurements, an average background concentration System (GEMS) Water Programme; Water Resources of 165 mg/l was used. Information System of India, India, and literature B1.3 Calculation of in-stream concentrations research. River concentrations are computed by combining Biochemical Oxygen Demand Model the loadings of the various substances with the The BOD model calculations are compared to dilution capability of the river discharge in each grid observations in Figure B.3a. This figure contains cell. Non-conservative substances (FC and BOD) measured data from 2902 Latin American stations (in then decay downstream. Standard one dimensional total 36,756 measurements), 21 African stations (in stream equations from Thomann and Mueller (1987) total 523 measurements), and 648 Asian stations (in as described in Voß et al. (2012) are used for these total 41,851 measurements). The agreement of model calculations. These equations perform a mass balance outcomes with observations is considered acceptable between loadings and receiving water and account considering the approximations of the model, the for the decay of non-conservative pollutants as they uncertainties in the data, and the scale of the coverage travel downstream by assuming first order decay. of the model. Thousands of points are quite close to The decay coefficient of BOD is assumed to bea the 1:1 line in Figure B.3a but not visible because they function of river temperature (Thomann and Mueller, are overlapping. 1987, Punzet et al., 2012). The decay coefficient of An important criterion for judging the performance FC is assumed to be a function of solar radiation, of any model is to consider the purpose of the model temperature, and the settling rate of bacteria and modelling application. In the case of this pre- (Thomann and Mueller, 1987; Reder et al., 2015). TDS study, the purpose of the model was not to compute is modelled as a conservative substance with no decay. concentrations exactly, but to estimate “pollution The final concentration of each grid cell is routed classes” (e.g. low, moderate, severe) as defined in towards the river mouth following a high-resolution Chapter 3, Table 3.8 for BOD, for example. Results drainage direction map (Lehner et al., 2008). in this form are more meaningful for assessments B1.4 TP retention in surface waters because they conform to the approach used by TP retention is calculated on river basin scale. The countries and river basin managers to interpret the conceptual approach and the parameter settings status of their own freshwaters (national water quality are based on Behrendt et al. (2002), where nutrient standards typically divide the range of water quality

Appendix-11

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conditions into “high”, “low” and “medium” classes of The scatter plot (Figure B.5a) shows the same spread as water quality). for BOD and FC. However, the agreement between model Figure B.3b shows that the model computes the same and observations is not as symmetrical as it is for BOD pollution class for BOD as observed in two-thirds of and FC, indicating more bias in the TDS model than in the grid cells with measurements. In more than 80 per the other models. On the other hand, the comparison of cent of the grid cells the model computes the correct computed and observed pollution classes (Figure B.5b) class plus or minus one class. shows a more than 80per cent agreement in pollution classes between model results and observations. In Faecal Coliform Bacteria Model 90 per cent of the grid cells the model computes the The model results of FC versus observations are shown correct class plus or minus one class. in Figure B.4a. The following measurements were available for this comparison: 2818 Latin American Total Phosphorus (TP) Loading Model stations (in total 47,888 measurements), 485 African The testing for phosphorus was somewhat different stations (in total 14,068 measurements), and 501 than for BOD, FC or TDS, because in this pre-study the Asian stations (in total 24,577 measurements). Again, model was used only to compute the loadings of total most of these measurements are close to the 1:1 line, phosphorus from lake basins into lakes, not the in- but not visible because they overlap. stream concentrations of phosphorus. The model performance as indicated by the scatter In testing the model, its performance was examined plot (B.4a), and comparison of FC pollution classes through computing TP loads from both lake basins and (B.4b) is as satisfactory as that of BOD. river basins due to insufficient lake data, and because Total Dissolved Solids Model the model should perform equally well in computing loads from large lake basins as large river basins. A comparison of calculated versus observed TDS is shown in Figure B.5a. The figure is based on a set of A comparison of calculated versus measured TP measurements that were available for Latin America, loadings into selected lakes is given in Figure B.6. Far Africa and Asia: 760 Latin American stations (in total fewer data were used for this comparison than for the 18,040 measurements), 1,544 African stations (in total other water quality parameters. For this selection of 162,551 measurements), and 655 Asian stations (in data, agreement of the model with measurements is total 33,656 measurements). quite good.

a) b)

Figure B.3: a) Observed versus calculated (WorldQual) biochemical oxygen demand for the period 1990–2010 for stations from Latin America, Africa, and Asia between 1990 and 2010. Vertical streaks of data are an artefact of data collection and processing. Units are in mg/l. b) Measured and simulated BOD in-stream concentrations were grouped into three water pollution classes which were derived from thresholds given by governments and international organizations. The difference in classes between observed and simulated in-stream concentrations was determined and displayed as percentage of grid cells (having measurements) in which a difference occurred between the observed class (see Table 3.8) and the computed pollution class. “0” indicates that there was no difference between the observed and computed pollution class. Same data set as for Figure B.3 (a).

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a) b)

Figure B.4: a) Observed versus calculated (WorldQual) faecal coliform bacteria for the period 1990–2010 for stations from Latin America, Africa, and Asia between 1990 and 2010. Vertical streaks of data are an artefact of data collection and processing. Units are in cfu/100ml. b) Measured and simulated FC in-stream concentrations were grouped into three water pollution classes which were derived from thresholds given by governments and international organizations. The difference in classes between observed and simulated in-stream concentrations was determined and displayed as percentage of grid cells (having measurements) in which a difference occurred between the observed class (see Table 3.1) and the computed pollution class. “0” indicates that there was no difference between the observed and computed pollution class. Same data set as for Figure B.3 (a).

a) b)

Figure B.5: a) Observed versus calculated (WorldQual) total dissolved solids for the period 1990–2010 for stations from Latin America, Africa, and Asia between 1990 and 2010. Units are in mg/l. b) Measured and simulated TDS in-stream concentrations were grouped into three water pollution classes which were derived from thresholds given by governments and international organizations. The difference in classes between observed and simulated in-stream concentrations was determined and displayed as percentage of grid cells (having measurements) in which a difference occurred between the observed class (see Table 3.12) and the computed pollution class. “0” indicates that there was no difference between the observed and computed pollution class. GEMStat data are not used for this scatter plot so as to avoid overlap with the stations used to estimate TDS background concentrations (Section B1.2.9). Also stations influenced by marine saltwater intrusion were omitted.

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Figure B.6: Observed versus calculated (WorldQual) total phosphorus loads per lake basin or river basin area for the period 1990–2010 for worldwide stations. Units are in kg/km2/year.

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B2 Water quality standards Latin American and Asian countries were compiled. To establish the thresholds of water pollution classes European and American standards were also for FC, BOD and TDS (Tables 3.1, 3.8, 3.12 in Chapter consulted. 3.) the below water quality standards from African,

Table B.5: Default TDS event mean concentrations (EMC).

Description Country Reference

Water quality standards for protected areas, source water, drinking water, China MEP (2002) aquatic fauna, industry, agriculture Water quality standards for primary contact, irrigation, aquaculture, sailing, Costa Rica Mora and Calvo (2010) and animal farming Water quality standards for primary contact Europe, EEC WHO (2000) Water quality standards for bathing and swimming, irrigation South Africa DWA (1996), Britz (2013) Water quality standards for primary contact Colombia WHO (2000) Water quality standards for primary contact Cuba WHO (2000) Water quality standards for primary contact Ecuador WHO (2000) Water quality standards for primary contact Puerto Rico WHO (2000) Water quality standards for primary contact USA, California WHO (2000) Water quality standards for primary contact Venezuela WHO (2000) Water quality standards for primary contact France WHO (2000) Water quality standards for primary contact Uruguay WHO (2000) Water quality standards for primary contact Peru WHO (2000) Water quality standards for primary contact Brazil WHO (2000) Water quality standards for primary contact Israel WHO (2000) Water quality standards for primary contact Japan WHO (2000) Water quality standards for primary contact Mexico WHO (2000)

Table B.7: Collected BOD water quality standards of different countries.

Description Country Reference

Freshwater standards Brazil Ministry of the Environment, Brazil (1984–2012) Ministry of Agriculture of the People's Republic of Agriculture water use standards China China + FAO River water quality Egypt El Bouraie et al. (2011), Egyptian law 48/1982 Drinking water quality and outdoor bathing India CPCB (2007–2008) standards Freshwater quality standards (fisheries, Japan Ministry of the Environment, Japan conservation) Freshwater standards Mexico Mexican Official Standard (NOM-001-ECOL-1996) Water quality standards for drinking water, Pakistan adopted from WWF (2007) aquatic water, and irrigation water freshwater species South Africa DWA (1996) Surface water quality standards Taiwan EPA Taiwan (2010) Drinking water quality standards Tanzania Environmental Management Act (2004) Surface water quality standards Thailand Pollution Control Department (2004)

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Table B.8: Collected TDS water quality standards of different countries.

Description Country Reference

Ministry of the Environment, Brazil Freshwater standards Brazil (1984–2012) Agriculture water use standards China FAO (2013) Egyptian law 48/1982 in El Bouraie River water quality Egypt et al. (2011) Water quality guidelines for irrigation water use FAO Ayers and Westcot (1985) Water quality standards for irrigation, industrial cooling, Japan Ministry of the Environment, Japan controlled waste disposal Water quality standards for domestic, industry, and agriculture South Africa DWA (1996) water use Water quality standards for domestic and irrigation water use Kenya Water Quality Regulations (2006) Moroccan regulation on irrigation Water quality standards for irrigation water use Morocco water quality (2002) Water quality standards for drinking water use Oman Victor and Al-Ujaili (1999) Water quality standards for drinking water, aquatic water, and Government of Pakistan (2008), Pakistan irrigation water WWF (2007)

To establish levels of concern of water quality parameters with respect to inland fisheries, water quality standards were consulted (Table 3.7 in Chapter 3).

Table B.9: Collected water quality standards also with respect to inland fisheries

Reference Water quality parameter

EPD (2011) Chloride European Commission (2006) BOD, Oxygen Geneviève M.C. & C.J. Rickwood (2008) Ammonia, Oxygen, pH LAWA (1998) Ammonia, BOD, Chloride, Oxygen Manivanan, R. (2008) BOD Michigan Water Quality Standards (1994) Oxygen, pH U.S. EPA (1986, 2015) Ammonia, Chloride, Oxygen, pH UNECE (1994) Oxygen

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B3 Literature on vulnerable groups Table B.10: Literature consulted for data on percentage of population coming in contact with polluted water, and for estimating the most vulnerable groups to pathogen pollution. Most vulnerable groups Other vulnerable groups Continent/country/region (e.g. “women washing For example: “Poor people bathing; Publication within country clothes, children bathing; poor farmers using polluted … “) irrigation water;…”

Adeoye et al. (2013) Nigeria

women (more “young North central children fetching water female” than “adult female”) fetching water children (2–14 years) adult men fishing, fetching water, Aiga et al. (2004) Ghana, Ashanti Region swimming (play and exercise) bathing

Barbir and Prats Mozambique, N’Hambita women body and laundry Ferret (2011) Village, Sofala Province washing people in the Peninsular children under 12 years & large Malaysia, Peninsular Choy et al. (2014) Malaysia compared to the households (more than 7 family (West) and Sabah (East) state of Sabah (East Malaysia) members) Day and Mourato children playing in and China, Beijing Region (1998) around the river

Engel et al. (2005) Ghana, Volta River Basin children

Papua New Guinea, women journeys to collect children or teenagers journeys to Feachem (1973) Highlands water collect water

Gazzinelli et al. Brazil, Nova União children playing and fishing (1998) female (10–19 yrs.) using Gazzinelli et al. Brazil, Rua da Grota water for domestic and (2001) hygienic activities Kabonesa and Happy, women using water for children collecting water for Uganda March (2003) domestic purposes domestic use

Lindskog and women collecting water, Malawi, Rift Valley children bathing Lundquvist (1989) bathing, laundry women collecting water, Manyanhaire and Zimbabwe, Mutasa bathing, doing laundry, Kamuzungu (2009) District cooking Mazvimavi and men carrying water for Botswana, Ngamiland Mmopelwa (2006) drinking and cooking 28% of poorest income second, third and fourth income North and Griffin quintile using water from quintile using water from springs, Philippines, Bicol Region (1993) springs, lakes, or rivers as lakes, or rivers as main source (20% main source each) female adolescents (10–19 women collecting water, household Sow et al. (2011) Senegal, Ndombo village yrs.) bathing, collecting water activities

Thompson et al. Kenya, Uganda, Tanzania women drawing water children drawing water (2001)

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B4 Lake data Table B.11: Data for lakes used in Chapter 3.

Continent Lake/reservoir Basin area [million km2] Lake surface area [million km2]

Africa Victoria 0.263 0.0670 Africa Tanganyika 0.238 0.0328 Africa Malawi 0.130 0.0296 Africa Turkana 0.073 0.0077 Africa Volta 0.402 0.0074 Asia Balkhash 0.174 0.0174 Asia Issyk-kul 0.010 0.0062 Asia Urmia 0.051 0.0049 Asia Qinghai Lake 0.019 0.0044 Asia Boeng Tonle Chhma 0.058 0.0026 Europe Baikal 0.584 0.0317 Europe Ladoga 0.271 0.0177 Europe Onega 0.054 0.0098 Europe Vaenern 0.048 0.0056 Europe Kuybyshevskoye 1.187 0.0050 North America Superior 0.207 0.0819 North America Huron 0.575 0.0597 North America Michigan 0.180 0.0573 North America Great Bear Lake 0.145 0.0305 North America Great Slave Lake 1.006 0.0278 South America Itaparica 0.497 0.0087 South America Titicaca 0.057 0.0082 South America Lagoa Mirim 0.046 0.0039 South America Tucurui 0.757 0.0034 South America Itaipu 0.840 0.0024

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and stormwater management. Available online: http:// Water Quality Regulations (2006): Ministry for the www.unep.or.jp/ietc/Publications/TechPublications/ Environment and Natural Resources, Kenya. http:// TechPub-15/main_index.asp (accessed August 2008). www.elaw.org/node/2261 UNEP (2015): The UNEP Environmental Data Explorer Weedon, G.P., Balsamo, G., Bellouin, N., Gomes, as compiled from World Population Prospects, the S., Best, M.J., & Viterbo, P. (2014): The WFDEI 2012 Revision (WPP2012) United Nations Population meteorological forcing data set: WATCH Forcing Division. United Environment Programme. http://ede. Data methodology applied to ERA-Interim reanalysis grid.unep.ch (accessed February 2015). data. Water Resources Research 50(9): 7505-7514, UNEP/GEF (UNEP Division on Global Environment doi:10.1002/2014WR015638. Facility) (2009): Municipal wastewater management WHO (World Health Organization) (2000): Monitoring in the Western Indian Ocean region: an overview bathing waters – a practical guide to the design and assessment. Technical Report Series, 2009/3, 83 pp. implementation of assessments and monitoring Van Drecht, G., Bouwman, A.F., Harrison, J., & programmes, London and New York, 311 pp. Knoop, J.M. (2009): Global nitrogen and phosphate WHO (Regional Office for the Eastern Mediterranean) in urban wastewater for the period 1970 to & CEHA (Regional Centre for Environmental Health 2050. Global Biogeochemical cycles, 23, GB0A03, Activities) (2005): A regional overview of wastewater doi:10.1029/2009GB003458. management and reuse in the Eastern Mediterranean Van Houte, J. & Gibbons, R. (1966): Studies of the Region. WHO-EM/CEH/139/E, Cairo, Egypt, 67 pp. cultivable flora of normal human feces. Antonie van WHO/UNICEF Joint Monitoring Programme (JMP) Leeuwenhoek 32, 212e222. (2013): Country files (1980–2011) – updated April Verzano, K. (2009): Climate change impacts on flood 2013 http://www.wssinfo.org (accessed September related hydrological processes: further development 2013). and application of a global scale hydrological model, Williams, R., Keller, V., Voß, A., Bärlund, I., Malve, O., PhD thesis, University of Kassel, Germany, 166 pp. Riihimäki, J., Tattari, S., & Alcamo, J. (2012): Assessment Verzano, K., Bärlund, I., Flörke, M., Lehner, B., Teichert, of current water pollution loads in Europe: Estimation E., Voß, F., & Alcamo, A. (2012): Modeling Variable of gridded loads for use in global water quality models. River Flow Velocity on Continental Scale: Current Hydrological Processes 26(16): 2395–2410. Situation and Climate Change Impacts in Europe. World Bank (1991): Staff Appraisal Report, China, Journal of Hydrology 424-425: 238–251. Tarim Basin Project, Agricultural Operations Division, Victor, R. & Al-Ujaili, S.R. (1999): Water Quality and Asia Regional Office, 167 pp. Management Strategies of Mountain Reservoirs in Ardi World Bank (1999): Environmental Management Northern Oman, In Goosen, M.F.A., and Shayya, W.H. Studies Report, Integrated Environmental (Eds.) Water Management Purification & Conservation Management in the Tarim Basin, Overseas Projects in arid climates, Volume 1 Water Management, 307– Corporation of Victoria. 350. Wondie, T.A. (2009): The impact of urban storm water Voß, A., Alcamo, J., Bärlund, I., Voß, F., Kynast, E., runoff and domestic waste effluent on water quality of Williams, R., & Malve, O. (2012): Continental scale Lake Tana and local groundwater near the city of Bahir modeling of in-stream river water quality: a report Dar, Ethiopia. Cornell University, 48 pp. on methodology, test runs, and scenario application. Zubrzychi, L. & Spaulding, E. (1962): Studies on the Hydrological Processes 26(16): 2370–2384. stability of the normal human faecal flora. J. Bacteriol. Water Affairs South Africa (2011): 2011 green drop 83(5): 968e974. report, Water Affairs South Africa, 24 pp.

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Appendix C

C1 Case study 4 – Chao Phraya

Table C.1: Water Quality Index in the Chao Phraya River Basin and Tha Chin River Basin (DO = dissolved oxygen, BOD =

biological oxygen demand, TC = total coliform bacteria, FC = fecal coliform bacteria, NH3 – N = ammonia nitrogen).

Min - Max, Median, and Percentage*

DO TC FC NH – N Water Body WQ Class BOD (mg/l) 3 (mg/l) (MPN/100 ml) (MPN/100 ml) (mg/l) 3.2 – 8.2 0.7 – 2.8 450 - >160,000 <180 – 54,000 ND – 0.45 Upper Chao 2 5.4 1.4 6,000 1,350 0.12 Phraya 18% (5/28) 57% (16/28) 50% (14/28) 43% (12/28) 100% (28/28) 1.1 – 7.6 0.9 – 4.4 3,300 – 35,000 200 – 17,000 <0.02 – 0.51 Central Chao 3 3.1 2.0 7,900 1,300 0.19 Phraya 20% (4/20) 55% (11/20) 85% (17/20) 90% (18/20) 95% (19/20) 0.1 – 5.5 1.8 – 7.7 1,100 - >160,000 400 - >160,000 0.20 - 2.30 Lower Chao 4 1.2 4.1 24,000 7,900 0.85 Phraya 38% (9/24) 50% (12/24) 46% (11/24) 29% (7/24) 29% (7/24) 1.8 – 7.5 1.1 – 8.2 200 – 54,000 120 – 4,900 <0.10 – 0.18 Upper Tha 2 3.1 3.8 4,900 780 0.10 Chin 19% (3/16) 6% (1/16) 63% (10/16) 53% (8/15) 100% (16/16) 1.0 – 7.0 1.2 – 8.2 2,700 – 160,000 450 – 92,000 <0.10 – 0.49 Central Tha 3 2.4 4.2 11,000 1,200 0.10 Chin 25% (3/12) 17% (2/12) 67% (8/12) 75% (9/12) 100% (12/12) 0.7 – 5.6 1.4 – 9.6 3,300 – 540,000 200 – 240,000 <0.10 – 2.09 Lower Tha 4 2.2 4.5 28,500 4,900 0.61 Chin 50% (14/28) 43% (12/28) 39% (11/28) 32% (9/28) 39% (11/28)

Standard Class 2 > 6.0 < 1.5 < 5,000 < 1,000 < 0.5

Standard Class 3 > 4.0 < 2.0 < 20,000 < 4,000 < 0.5

Standard Class 4 > 2.0 < 4.0 - - < 0.5

* Percentage of the measurement that meets the standard of surface water quality (a total of the standardized measurement/a total of all measurements) (Source: Thailand State of Pollution Report 2013, PCD)

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C2 Case study 5 – Vaal

Table C.2: Resource Quality Objectives (RQOs) for salinity in priority Resource Units in the Upper Vaal WMA (only a few results are illustrated here). Threshold Indicator/ Numerical RU RQO 95th %ile Context of the RQO of Potential measure limit Concern (TPC)

Local industrial activities are having a negative impact on the water quality Salts need to causing salinization of the Taaibosspruit. be improved to Salt concentrations should be improved levels that do to a D category. Where available the 95th Electrical RU67 not threaten ≤ 111 mS/m 79.1 percentile of observed or modelled data 98 mS/m conductivity* the ecosystem has been provided. The 95th percentile and to provide threshold is a standard procedure for users. which has been selected to remove the extreme values considered to represent outliers.

Salts: Upstream mining activity releases have causes acid mine drainage conditions in the system. The salts Salts need to need to be returned to a state where be improved to it is not having a serious impact on the levels that do Electrical ecosystem, i.e. a D category. Where RU71 not threaten ≤ 111 mS/m 87 98 mS/m conductivity* available the 95th percentile of observed the ecosystem or modelled data has been provided. and to provide The 95th percentile threshold is a for users. standard procedure which has been selected to remove the extreme values considered to represent outliers.

Electrical ≤ 111 mS/m 90.5 98 mS/m conductivity* Salt loads associated with acid mine drainage impacts from upstream mining activities are of concern for the Salts need to ecosystem and also for downstream be improved to users. The salt concentrations should levels that do be managed to a D category. Where RU73 not threaten available the 95th percentile of observed the ecosystem Sulphates* ≤ 500 mg/L 132 or modelled data has been provided. 350 mg/L and to provide The 95th percentile threshold is a for users. standard procedure which has been selected to remove the extreme values considered to represent outliers.

Electrical ≤ 85 mS/m 84 70 mS/m conductivity* Excessive salt in this system causes salinisation of agricultural land and also fouling of industries. It is also a potential Salts need to problem for maintenance of the Orange- be improved to Vaal largemouth yellowfish population, levels that do recruitment of which may be sensitive not threaten to high salt loads. Salt concentrations RU75 the ecosystem must be improved to a C category. especially fish Sulphates* ≤ 200 mg/L 173 Where available the 95th percentile of 140 mg/L and to provide observed or modelled data has been for users. provided. The 95th percentile threshold is a standard procedure which has been selected to remove the extreme values considered to represent outliers.

Appendix-27

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Appendix-28

Buch_UNEP_zAnnex_1504.indd 28 09.05.16 17:08 www.unep.org United Nations Environment Programme P.O. Box 30552 - 00100 Nairobi, Kenya Tel.: +254 20 762 1234 Fax: +254 20 762 3927 e-mail: [email protected] www.unep.org

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